RV toilet repair does not seem to be one of the services repair shops specialize in. In fact, we wanted upgrade some older parts prior to our departure but even after calling dozens of shops we could not find anyone that seemed willing or competent to help us.
So we were cautiously optimistic that this outfit in Hixon, TN mentioned by the manufacturer would be able to help. Located near Chattanooga, TN it was somewhat out of the and East of our planned route. Given the high priority of this particular repair we also cancelled one of our initial stays.
To summarize, the follow we met, David, was an independent contractor that had many years experience with our particular system, the same system found on many boats which is main business.
We both agreed that given the age of our system it was a good time to replace most all of the parts that typically have limited lifespan. Not only knowledgeable but very personable and thorough. Each part was removed, working in a very cramped space.
The finished product was nor cheap but all practical purposes, we ended up with a new toilet that should serve us well for years to come.

Getting a messy job done