Hi Ron, re-drilling the friction material was in hindsight a better plan. I was concerned about breaking the friction material though.
I've now drilled through the clutch driving gear and reassembled it with new friction material and new friction plates. I'm now having a problem that the clutch is not disengaging properly. I've adjusted it as much as I can, but there doesn't seem to be enough free space in the clutch to allow it to fully disengage, and hence it drags and makes it difficult to get into neutral. I read elsewhere on the forum of a similar issue with replacement BSA clutch plates being too thick.
Does anyone know of a way to resolve this? Will the clutch wear down/bed in, or will I need to put the old plates back in? (They didn't seem worn and may well have been new when I put them in, but I don't remember as it was too long ago!).
I've not tried riding the bike yet so don't know how much the dragging will affect it?