Glad to hear you got it running. It is a model 71 with a 122 motor and # 122 decals. They probably picked up a couple of 122 decal numbers when they put the 12 hp. engine in the tractor, and replaced the #71 with them.
I'd imagine they probably swapped the hood along with the engine from a 122 parts tractor instead of applying new decals...with the way the decals are faded along with the hood paint and such, seems likely they're original.