a friend of mine is in San Marcos Texas and sent me these pictures. Apparently this is one of one Prevost MHs built in 1951. It was owned by a gentleman from Montana.
I agree on the "bus conversion". It still has the old destination indicator above the windshield.
Some years back, I saw a conversion of a 30' Leyland double decker bus. It still had the roller in the destination indicator with all the original routes in it, and the owner's kids kept changing the display. I don't think I'm brave enough to drive a 14' 6" tall RV!