Into the final detailing stages now...
I've been mulling over several different ways to add visual interest to those big, blank areas on the upper and lower surfaces of the main engine housings, and I think this is the version I like best. Basically, these are massive heat sinks tied directly into the engine coolant loops. In addition to having a plausible function, I love the way they add a bit of mechanical flair to the overall look.
I have also added the hexagonal thermal tiles to the bottom of the lander module, hull plate texturing to the registry number, warning icons for the maneuvering thrusters, and various other little things here and there.