...for completeness, I ordered 4 new yamaha valves.

even at mates rates (no carriage, and possibly vat...) they are still horrific.
But the pattern parts I got didn't fill me with confidence, and I figure its probably not worth it... i could probably have re-used the 2 exhaust ones but thought "ach, f'ck it, don't be so tight, replace them"...
ouch. I said, I'd collect them after the end of the month!
a