Just a happy note to say I picked up a very decent 5H1 (XV920) left-hand silencer on ebayUK this week.
In fact it is in rather better condition than the righthand 5A8 unit into which both cylinders currently feed, courtesy of some previous owner.
Now I'm still looking for a 5A8-14611-00 rear header pipe, if anyone's got a spare! I will otherwise get my local exhaust specialist to make a forked pipe to feed that cylinder into both silencers, as per original.
At least my TR1 now looks symetrical!
Nick, Norfolk, UK