This type of shuttlecraft had two nacelles, attached to the sides near the ventral hull with two pylons each, and two impulse thrusters facing aft. These thrusters were above and to the side of the rear hatch. The shuttles also had a small, stub wings on the craft's center line. There was also four maneuvering thrusters, located near the corners of the craft. There were two side doors, and the shuttle had a large forward facing window, on the dorsal side of the front of the craft. The forward ventral hull had a large black surface, and a series of landing lights were located in the center of the ventral hull. (Star Trek V: The Final Frontier)
The interior of the shuttle had two forward facing seats in the cockpit, with a large center screen located between them.
The main cabin had two rows of lights running the length of the ceiling, with a handrail running just below each light. There were inward facing bench seats that lined the sides of the craft with track lighting located beneath them.
Shuttles had three weapons lockers located throughout the craft, two were located just aft of the side doors, one on each wall, and there was one located below the center screen in the cockpit. (Star Trek V: The Final Frontier)
Shuttles of this type
In the script of The Final Frontier (scene 56), the shuttle was described as having retractable wings and of such size that "even with wings retracted, the Galileo clears the door with only a few feet on either side."  These notions were not transferred onto the full-scale mock-ups and studio models.
While never stated on-screen, the in-universe dimensions of the Galileo-type shuttlecraft were apparently intended to be 30×13.5×8 feet (9.14×4.11×2.44 meters) without engines, according to information from the 40 Years of Star Trek: The Collection auction catalog (part two, p.225) and American Cinematographer, (issue July 1989, p. 80).