Hi Pevans70737,
The doors are probably made by Southco, a Lippert subsidiary. The locks are probably
Fastec. I think a locksmith can get a master key from Fastec that allows removal/replacement of the core so a new lock can be installed. You should probably call Fastec to ask. Or call a local locksmith. But I'd start with local locksmith storefronts. Don't just call around from a Google search. There have been lots of news stories about crooked phone operations that start by damaging the existing lock and then they stick you with a huge bill.
If you can get inside, by removing the door lock you should be able to get the key code and you can order replacement keys from Fastec.
The cargo hatches and other exterior locks are probably commonly available keys. Southco R001 and a CH751