Thanks for the comments folks! I'm enjoying this one a lot. Got the base colors on and started final assembly, I'll try to post up some pics today or tomorrow.
The model is 1/120ish, about 8" long. But there's a lot of surface area, so it doesn't seem "small" once put together. As always I wish it was bigger.

Bondo squish is pretty easy...I really should finish up my new website so people can see how I've used it before. Basically if you need to make a recessed area that's difficult to build, make a negative of it and squish it into Bondo polyester putty, then remove once it hardens. In this case it's just lines scribed into plastic sheet. Cut an opening larger than the piece, so you'll end up with enough Bondo after squish for some durability. Coat the part with mold release (vaseline, spray release, chapstick, etc), fill the recess with Bondo, and squish it in, then remove when the Bondo hardens but is still a little soft. I got some bubbles this time, but they can be wear and tear. The vent before was just a simple recessed square with no detail and a big honkin' seam right down the middle.

I figured there should be some kind of grill in there, as it echos the Imperial Shuttle design.
More pics soon...