I tried a lot of different things on this model.
The Engine Bells were from the kit, but I detailed them by scratchbuilding all the lines on them.
The cockpit windows were from the kit, but I put a second layer ( individually cut, formed and sanded ... ) over top of them to try to replicate the actual windows.
The main landing gear doors were detailed with aluminum foil and styrene strip ( to add some structure ) .
The landing gear have brake lines added to them.
The drogue chute container was added to the tail.
The RCS on the nose were drilled out and replaced by plastic tubes.
The elevons were cut off and replaced in a dropped position.
The StarTracker ports were drilled out and backed with styrene.
So all these little things took some time. I guess the only 'bump' along the way was the repeated filling and sanding of the belly. The seam just didn't want to go away.
All tolled, I spent about 65 hours on this model ... not including research time. The single most time consuming element was applying the 'white' tiles. Each one was cut out and applied and this took about 10 hours. I also used small strips of painted aluminum foil on the front of the OMS pods and around the cockpit windows to replicate the thermal tiles.
Working with surgical tape was a lot easier than I thought it would be, and, I think, the scale effect is pretty good.
I do appreciate your positive comments! Thanx very much.