I can see a new tranny and engine running into the $20,000 area, Busnut. I guess on the bright side you know it will never have to be done again. When I changed fuel filters on mine I discovered that the filters had blue paint on them matching the engine which looks fairly fresh compared to what generally would be in a 37 year old bus! I have no idea if that's good or bad but at some time the ole girl has been refreshed. Later
It could very well be that the engine was given a spray paint rebuild to sell the bus. I would think if an engine was pulled and rebuilt that it would be painted without the fuel filters attached, but what do I know?