Antichrist said:
As others have said, sell it to a collector if you don't want to keep it original. I would hesitate to even modify it with bolt-ons. Too tempting to drill holes in it.
When I restored by Bantam T3-C, I made sure that the original springs, Fulton hitch and safety chains I replaced were cleaned, coated with rust preventative, wrapped and stored away in case I have need for my trailer to be 100% original again.
As for the hitch, rear receiver, covered wagon top and other modifications, all were designed to be installed without any welding or cutting. However, as for holes, sometimes that is the only way. I had to drill a few small ones, but they can be filled (with metal, not bondo).
Still, that trailer is a fast disappearing piece of military history which cannot be replaced. Sell it to a military vehicle collector and buy a U.S M416 or Canadian M101. You (and the collectors) will all be happier in the long run.