A couple potential problems here: a) it's likely that the headset is threaded at 26tpi, the "old Raleigh" thread. You won't be able to find a modern HS with that thread, so if yours is trashed you might be looking at a new fork with standard 24tpi threading. The other HS parts will fit. b) By riding it loose as you have been doing for 6 months, you might have ovalized the headtube. If that's the case the fixed cups won't really be fixed but will sort of rattle around in the tube. If the HS itself is not actually pitted (lucky you) you might be able to fix the cups in place with some JB Weld. I'd definitely stop riding it until you've torn it down to see if it's salvageable.