Cheapest one is the Alvin Gottlieb knocker on PSPA, I just brought one for my Data East Simpsons as it was missing, works great.
Yeah saw that one which gave me the idea. I have my SI set to very hard settings and don't win many games but when i do, it's a let down not hearing the bang
Just by the way, rtbb has data east ones for $30+ postage
