Jerry,
In another post here, I saw you were in Grand Junction. A few years back, I forgot to close the hole in the power cord reel bay, and the cord worked its way out of the hole and I dragged it (unknown to me until a motorist motioned me about while passing) on the ground for about 30 miles. It was toast. I found a travel trailer dealer in Grand Junction, Humphrey RV, who accommodated us the next day, even though they were not a MH shop and were very busy. If you are still in that area, I would give them a call.
That said, I think a muffler shop is your best bet.