Steve it is basically a window type unit like one would put in a house. So if you can find a company that can rebuild window units, they should be able to do the job for you. Problem is the tubes are so small it is difficult to put ports in them in order to recharge the system. Once those are in, it can be recharged if that is your problem.
I have only heard of one place that did this type work on an RV, and that was in north Alabama.
2001 Monaco Diplomat 40' PDQ - 08 Honda CR-V