No the number is gone. I was going to ask next. So it's stolen then? And I'm in trouble?
I don't know if you're in trouble or not... I think not as you obviously are unaware of the possibility that the engine is stolen even with the tell-tale cut wiring harness. You have a choice..... to keep your mouth shut and take a chance of having received stolen goods (if it is indeed stolen)... OR... if the seller can still be located, and you have a signed receipt, visit your local law enforcement department first with your tale, then hopefully you, accompanied, by an officer can visit the seller. I strongly suggest that you do not in any case visit the seller alone!
A suggestion.... look on the powerhead for a quarter sized core plug... looks like a small freeze out plug. It may have the model and serial number imprinted upon it. If so, that would tell us exactly what the engine is... and possibly the numbers would be on the stolen engine list if it is indeed stolen.