This is going to be my progress update for my bus hence forth called Corvus. So sit back and enjoy comments, encouragement, and suggestions are all welcome.
Cool looking bus! Are you short, or is that roof tall (you don't look all that short)? It looks like you have some decent head-room to work with, at any rate!
I treated the floor with ospho. Primed it with zinnser mold and rust primer. Filled all the holes from the seats with a polyurethane resin. (I would recommend the aluminum tape). The resin has a tendency to stay sticky. Put down a coat of blue enamel rustoleum oil based paint. I did the frame work with 1.5 X 3/4" X 8' premium pine. Cut 3/4" foam board to fill the gaps and laid 23/32" OSB board to cover it all. The windows are covered over with 20g paint grip galvanized steel. Glued in with construction grade gorilla glue and self taping sheet metal screws.
I used to ride a ford B700 1979 carpenter to school for a couple years.. we had a bus driver that would just put that thing to the floor all the time.. i remember those rides to school... when he drove, the heater blew so hot of air your legs burned... not sure how fast he drove but that bus took off quick as i remember... it was a gasser and looking back had an AT545 because it had the "whistle" shift from 1-2 like my current bus does...