Here's a bit more progress. I've been working on the forward... hole? for lack of a better term. It's amazing how much a difference it makes to have the pipes actually be modeled.
Here's another image which shows the work I've started on the center box shape. The more inboard areas are more or less done, but the forward area still have work left to do.
For those of you not familiar with the kit, here's this area on my old, OOB kit. The pipes don't really go anywhere. This has bugged me since I was a kid. I really like the improvement.