I recently ordered extra keys for the new door latch/lock that I installed after the original one failed. The original lock was Fastec and the new one is Trimark. They have keys for all of them, so all you need is the lock code from the door lock, usually inside the assembly when you take off the inside part, and they will mail your keys to you quickly.
https://www.easykeys.com/RV_Keys_Locks.aspx