The model is approx 32" high, 27" wide, 28" deep (81 cm. x 68 cm. x 71 cm.) and a diameter of 94" (238 cm.) It includes the original special effects side bars that fitted into two of the secondary thruster slots, and lowered the craft to the platform for landing, and was matted out in post production.
You can can browse a large collection of making-of stills, including pictures of the Aries 1B, on Douglas Trumbull's website.