Artorious,
Looks like you put a lot of time and energy into recreating one of your beloved SA pieces. Nice job! The only suggestion I would have is in regards to the left fender and skirt. On the first pic the skirt doesn't sit level up with the hull and you can see a gap between the skirt and the hull itself, a little bit of putty and sanding would fix that right up. Same with the front left fender matching up to the hull, there's a noticeable gap (maybe intentional?) there also.
I particularly like the attention to detail on the stowage as well as the subtle weathering. Not sure what additional weathering you are planning to add, but the current look is nice and subtle, especially with the dust on the lower hull being muted somewhat because of the side skirts. Add a little dust to the wheels themselves to tie in the dusty running gear look and you'd be set IMHO.
Good luck on #5, what are you considering for your next project in SA colors of course?