All 4age's rotor buttons should be roughly the same. I had a smallport and a bigport dizzy side by side and the rotor button was slighlty different from the smallport, but I'm now using it in my bigport dizzy and no worries.
Repco should be able to get you a bosch one if you don't want to use the other one you have. But it should work.. I know you can still find brand new dizzy caps to suit 4age's aswell through bosch.