Just delivered, new motor arrived, this one is an inverter duty rated motor, that means spin it at 100 RPM and you won't be able to stop it by hand, or at least that is the idea. The GP motor you can stall easily with one hand, it is fine when the VFD frequency is above 30%, below that it'll struggle.
This is an eBay special so lets see if its working, keyway is there so that is a good sign. mmca will likely have to lathe a new pulley.
Uses a 145TC mount so it should just fit into the 56C I made a few weeks ago. The big difference is this motor is 22kilos/50lbs, which is more than double the GP motor, and around 8x the original weight.