Your trailer resembles some commercial lighting trailers. They are equipped with a small generator and a mast for lighting, for construction sites and such. Here's a picture of one I'm rebuilding to be a ham tower trailer, not the same as yours, but the heavy, low profile is similar. I agree that these little trailers will make great camping trailers. They are built very tough and have better road clearance than most consumer-type trailers. Plus, they are rather inexpensive after taken out of service, having bad generators, etc. This one had a military MEP-017A generator, 5 kw gas, which is overkill for me. I'll be adding batteries (24v, 150 AH) to the rear deck for power during extended camping trips or ham radio events.
Bob