Re: 1960 GMC PD4104
I like those pd4104's, they were quite an improvement over the 4103's mainly because of the flat floor and the air ride rear axle.
I also own a 4103 that I bought 8 years ago. It was vandalized by some kids where I had it parked when I lived in the city. Darn kids broke out the curved door glass and cracked the right windshield. I can't find a door glass at all and the windshield will cost about a grand or more by the time it's delivered. Great running bus, tho I sorta got afraid to take it too far from home because of the problem of finding parts in case of a breakdown. It was built in 1952 and served most of its working life working the towns around the bay area. Surprisingly, everything in it still works and is simple to repair.
It too was fully converted. I now use it as a guest house. The main reason I bought my '92 Ward is for the flat glass and floor, power steering, air ride rear axle, auto transmission ( so the wife can drive it ), and easy to get parts for. Horsepower is about the same, but I think the 6-71 has a bit more torque. The ex-Greyhounds ride a bit smoother but that may be because of the extra weight.
Keep us posted on your progress, that is one sweet looking ride.