I've got this old 8040 I'm fixing up to give to my son. I got everything working, but the power button cap is gone so you gotta kinda push in there with a guitar pick or something to fire the amp up. It's pretty inconvenient. Anybody know the part # on Mouser or some place to pick one up in the US? The only thing I could find was Tube Amp Doctor, but they're in Germany. 26 Euros to ship a 4 euro part sucks. Thanks!