wenglish I ran into a very similar situation with our Winnebago Class A when I had my catalytic converter stolen too. Two RV dealers the current Winnebago dealer and Camping World both declined. Told me to go to Ford. Local Ford dealer said they won't work on the F53 Chassis. The one they recommended never called me back.
Back when I bought my Winnebago the RV and Ford side were both under the same ownership so it was never an issue... until they split.
Finally, found a muffler shop that did the work and saved me about $1,000 in the process. But made me very concerned about what I would do if I actually had to get into a shop. Thankfully my local tire shop does repairs and they've done my Oil Changes and A/C work.
