[MJN]

The Greyhound bus museum in Hibbing, Mn has quite a few on display, GM and non-GM made. http://www.greyhoundbusmuseum.org/buses.html
and when you're done at the museum head up the road to the iron ore mine overlook and check out the GM powered haul trucks.
https://hibbingmineview.org/hull-rust-mine-view/

A couple years back they had bus owner group come to town and had a bus parade though town.