(written from a Production point of view)
Beginning in 2009, Revell (Germany), Revell-Monogram's former German subsidiary until 2006 when it was split off, re-released some of these models and later produced new kits from Star Trek: The Original Series and Star Trek Into Darkness. Its former US parent company went out of business in 2018.
Revell-Monogram LLC was formed in 1986 when formerly independent US model kit companies "Revell", founded in 1943, and "Monogram Models Company", founded in 1945, were merged into one company by their then-owner "Odyssey Partners of New York", retaining both names, which was reflected in the new combined company logo featured above in the introduction. The company has subsequently changed hands several times over the course of its existence.
Revell itself had established a German subsidiary in 1956, which split off from the mother company in 2006 in preparation for the company's acquisition by radio-controlled airplane maker Hobbico Inc., and became a fully European-owned independent company as "Revell GmbH & Co. KG".
It was around that time that Revell GmbH renegotiated the Star Trek license extension exclusively for the European Union. As indicated hereafter, its new owner Hobbico was apparently not interested in a renewed/extended license for the US market, presumably because it felt that consumer interest in the Star Trek franchise had reached an all-time low in the US at that time. (see: Demise of "The Franchise" in the prime universe)
The company was also the licensed producer of model kits from the Battlestar Galactica and Babylon 5 franchises, whereas the German iteration currently holds EU licensing for the Star Wars franchise, having taken over that license (and its production molds) from Airfix, the renowned British model kit company.
The American company's name was reestablished as the "Revell Group" when Hobbico formally took control of the company in May 2007, but ceased to exist altogether when Hobbico itself declared bankruptcy in June 2018.
Star Trek association
Revell-Monogram produced a limited number of kits while it had the Voyager license, including the USS Voyager itself, a Kazon raider, and the Maquis raider. It also produced a three-piece set containing all of these ships in a smaller scale and an even smaller, pre-painted set of snap-together models of the three.
In 1997, a "limited edition" version of Voyager was produced, with an open shuttlebay, an in-scale Type 8 shuttlecraft, revised decals and detailing, and Revell-Monogram's last addition, what it called a "Kazon torpedo".
Despite rumors of the possible production of a Delta Flyer model, Revell-Monogram never issued another kit.
The company, despite already being a merged entity, opted to release models under its separate brand names: "Monogram" for the US and "Revell" (through its German subsidiary) for Europe. The special edition Voyager from 1997 was the only exception to this branding.
Unlike AMT/Ertl (the original Star Trek model kit company that had lost out on its bid for the Voyager license), which had only done so for two of its Star Trek: The Motion Picture and the Deep Space 9 kits at the time, Revell specially commissioned photography of the actual production-used studio models. These photographs featured as box art for the kits and as an aid for the modelers, usually sticklers for accuracy, who had previously made do with low-resolution, blurry motion picture stills. 
The by-then independent German branch of Revell, Revell GmbH, sprang back into life in 2009, when they reissued the Voyager kits (excepting the Kazon torpedo), which were only released in Europe through a separate European license for Star Trek model kits. The company most likely acquired the production casting molds from its former American parent company during this period.
As a result, the status of licensing for North America has become unclear as not a single Star Trek model kit has been marketed or re-issued in North America since 1997 by what was now known as the Revell Group, nor are any likely to follow due to the turning over of the production molds to their former German subsidiary in 2007 (the same year that Round 2 LLC acquired AMT and Polar Lights). The bankruptcy of the former parent company's last owner in June 2018 has presumably meant the license simply expired.
For (new) American Voyager fans, this means that they will either have to wait for an American company to acquire such a license, with Round 2 LLC as owner of the only two other Star Trek licensed model kit companies as the most obvious candidate.
In December 2011, Revell Germany followed suit with its first truly new releases since 1997, now based on The Original Series, exclusively for the European market, as Round 2 holds the Star Trek license for the US. Kits of the USS Enterprise (NCC-1701) and the Klingon D7-class battle cruiser, both Revell originals and not AMT derivatives, differed in scale and tooling from their predecessors.
In May 2013, Revell-Germany scored a coup with its release of a model kit of the alternate reality Enterprise, on the occasion of the release of Star Trek Into Darkness. Though US company Polar Lights had already announced a release of this ship back in 2009, their product was continuously delayed and even cancelled in 2012, so Revell-Germany became the first company that released the very first licensed model kit based on the events depicted in the alternate reality, albeit it in Europe only.
The 2019 German Star Trek model kits reissues saw the box art synchronized with the packaging style introduced a year earlier by the two other officially licensed Star Trek model kit producers, AMT and Polar Lights.
At the start of 2021, the status of the American Voyager license was finally resolved when, as expected, Round 2 subsidiary Polar Lights slated the release of its brand new USS Voyager model kit for later that year. Planned as a part of its 1:1000-scale line, the old Revell-Monogram molds were (intentionally) not used and the models were designed and manufactured as Polar Lights originals. 
The announcement marked the first time since 1994 (when AMT lost out on Voyager to Revell-Monogram) that all officially licensed Star Trek model kits (save one) were reunified under one producer's roof for the North American market, as of 2021.
Star Trek releases
|USS Voyager||1:670||1995||3604||US release|
|1:1276||1996||85-3611||"Pre-painted" "Mini"-kit US release|
|06900||"Pre-painted" "Mini"-kit European release|
|1:670||1997||3612||Limited (20,000) Edition; included open shuttlebay; in-scale Type 8 shuttlecraft; improved decals; Voyager bonus pin; only combined company logo kit release; box-art by Randy Asplund|
|Maquis raider||1:323||1995||3605||US release|
|1:1276||1996||85-3611||"Pre-painted" "Mini"-kit US release|
|06902||"Pre-painted" "Mini"-kit European release|
|Kazon raider||1:458||1995||3606||US release; two variant issues are known with photos of the slightly differently angled model on each box cover|
|n/a||1996||85-3610||"Pre-painted" "Mini"-kit US release|
|06901||"Pre-painted" "Mini"-kit European release|
|Voyager 3-piece set||1:1400||1996||3607||Two variant US releases; "Bonus Value Pack" with glue, paint and brush included, and a regular issue without the bonus contents|
|05780||European "Bonus Value Pack" release; no regular kit release is known to exist|
|Kazon torpedo||1:35||1997||3608||US release|
|As Revell GmbH and for the EU market only|
|USS Voyager||1:670||2009||04801||EU-only reissue of 1995|
|2019||04992||EU-only reissue of 04801 (2009)|
|Maquis raider||1:323||2009||04809||EU-only reissue of 1995|
|Kazon raider||1:458||04810||EU-only reissue of 1995|
|USS Enterprise NCC-1701||1:600||2011||04880||EU-only release; includes optional decals for the USS Potemkin and the USS Constellation |
|2019||00454||EU "TechniK" release only; essentially a reissue of 04880, but now with lighting and sound effects rigs|
|04991||EU-only standard reissue|
|Klingon D7-class battle cruiser||2011||04881||EU-only release; tooled to approximate the appearance as seen in DS9: "Trials and Tribble-ations" |
|USS Enterprise||1:500||2013||04882||EU-only release|
|50th anniversary Set||1:600
|2016||05721||EU-only release; contains both reality versions of the USS Enterprise as previously released; glue and paint included|
- Scales courtesy of Starshipmodeler.com
- Components of the Voyager and Maquis raider kits were spliced together to form some of the background ships during the DS9 Dominion War saga, most notably the USS Yeager.
- The model of the Val Jean owned by Teero Anaydis in VOY: "Repression" is the small scale Maquis raider from the three-piece set.
- Good studio model reference material was still extremely hard to come by on the early 1990s internet, nor was much available in print besides occasional images spread across a multitude of more generic publications, be it licensed or unlicensed. Now defunct, "The IDIC Page", the first (and renowned by modellers) sophisticated Star Trek studio model reference website was launched by William S. McCullars in 1997, whereas the very first specialized print publication on the subject concerned the 1999 Japanese reference book, Star Trek: Official Guide 4 - Mechanics, though that book has remained a rarity outside Japan.
- It appears highly unlikely that Revell GmbH would turn over the production molds without sizable compensation while it also holds a Trek license, meaning that new sets of (very expensive) production molds would have to created. Fans are forced to try their luck in the secondary market (such as eBay, where the Monogram releases are less common and thus relatively expensive) or through the grey market acquisition of an European release, which, as related hereafter, is technically quasi-legal.
- Having remained unavailable in the USA, Producer Robert Meyer Burnett has related the lengths he had to go through to illegally obtain a copy of the kit in a February 2017 Word Balloon podcast interview (currently posted on YouTube), illegally since licensed non-US sellers such as Amazon.co.uk or Amazon.de are under the license stipulations prohibited to sell these to US/Canadian residents. Unlike individual customers like Burnett, retailers actually run the real risk of incurring stiff legal penalties when caught selling products to customers in markets they are not licensed for. Amazon in particular is not willing to run these risks and strictly adheres to such license stipulations. On the other hand and theoretically at least, eBay is formally an after-the-fact auction website for individuals selling each other (used) products and therefore far less susceptible to legal penalizing, again, in theory at least; Burnett got his (illegal) Enterprise copy through eBay – without legal ramifications, even though he remained punishable under Federal law, theoretically at least yet again.