Thanks Taffy, I'll pick one up. When did the valve cover add the second outlet? I just need to know what to ask for.
Regarding plugging the rear;
Yep, I've done that, but I'm taking it off every time to make tappet adjusting easier. Unfortunately it cuts it's lifspan dramatically.
I think the single breather would help me get the spanner in there without taking it off.
I really need to just weld some ears onto a 10mm socket for valve adjustments. It would be a fine tool for the job.
Back on topic, I had some checking on the upper part of the y-pipe. I scrubbed it up with a nail brush, hot water, and dish soap. Then warmed up a tube of "shoe goo" in the sun. I burned it in with a finger, then applied a few thin coats untill it was 3mm or so thick.
I rode it the next day and now it's got 50 hours use. I can't even peel it up where it's thin.
It might work on your boot hultz, at least long enough to ride it a bit while you source a replacement.