Casey,
Down here in Rolla, MO there is a Military salvage yard. They guy collects acres worth of old military trucks and accessories. Last time i checked he has 3 or 4 of these trailers. One is a round fender style that he says people like to collect so the price is higher(i didn't get that price)
He has two or three more that are in various states. One needs tail lights and it is ready to go. It has been compartmentalized inside and is painted white. It didn't notice any rust but there could be some there. I think the price for it was around 650-750 can't remember exactly what it was so don't quote me on that. The other few he has are rough. And by rough i mean need some metal work because of rust. I don't know the prices on these.
If you want a phone number PM me and I will try to get it to you.
lunyou