IIRC, until maybe the mid 1950s, you could still buy a GHQ from AHC for as low as $3.95. Made interesting paper weights.

That club member I mentioned actually claimed he had his running. Could turn a 13" prop over 5000 rpm. All he had had to do was hone and chrome plate the cylinder, turn a new piston to replace the stamped original, install a bronze shaft bushing, and a couple other little mods.