Hey man, this is looking really good so far!! Are you going to add a backdrop at all or some lighting?? I've found (and i wish i had a photo of it!!!) that a few strategically placed "warmish" lights around the back perimeter of the diorama can replicate daylight but be really subtle....I did this with a display i did of an African German airfield and it looked great!
Can't wait to see the finished work man!!!