crank pulley
You can get one turned (make) or repaired the old one from a machine shop. Just find a decent machine shop with a slotting machine, shaper or a milling machine with a slotting attachment, so they can either repair (I don't know what's wrong with the old one, if you tell me, I can tell you what to do) or turn (liyawanawaa) this in a lathe from cast iron and make the keyway in one of above machines. By the way this will be HALAL If they look towards Macca during the production process .