I've been away from this for a while thanks to other priorities taking over, but I was able to get back to work on it today!
The body trim has all been added, using a combination of Model Car Garage parts, styrene stock, tape, foil, and a set of door handles from Fireball Modelworks. Once that was done it was on to weathering - both to add the required gunk and also to reproduce the faded and dusty color.