You can get new cylinders. I know Out of Doors Mart has the cylinders for the KT 200 lock.
You can also get new compartment cylinders. I would also check with Inland RV and Vintage Trailer supply. You can find all of them with an internet search.
Me, I got lazy. I slapped on a keyed locking hasp made by Stanley for my main door and never lock it to OEM lock. I have the key but it's sticky. One of these days I will change it. If I remember right you don't have to pull the main door lock to change the cylinder. I think it can be forced out. But my memory never was that good.
By the way it is likely the main door cylinder is worn enough that any key for this lock will fit and work.
Sail on silver girl. Sail on by. Your time has come to shine.