I've gotten keys made at my local locksmith as well as a website called RV Locks and More. At RV Locks and More you can actually get all your cam locks replaced as keyed alike to your door key as well.
I changed out all of my locks to new locks that all have matching keys. There are only a few RV keys out there. Anyone who's ever owned an RV probably has a key to yours. After one trip with 3 different keys to my RV, I decided to change all my locks. It didn't cost that much, and now I have about 10 keys. Handy.