Aaaaarrrrrgggghhhhhh!!!!!!!!!!!
I waited for a while to see if e-bay would come up trumps but nothing happened...so I went and ordered one from Aprilia

It only arrived this morning and I'll be sticking it on tomorrow. I know I should have waited but I was getting fed up with not be out on the bike. Thanks for finding that one for me though Joe.
The clip-ons that I got from e-bay were a bit too low for me when I offered 'em up so I decided so go for an o.e. one. That does mean that I've got a nice pair for sale if anyone wants to make me an offer? They are the ones that were linked too earlier in the thread (in annodised black). They're a slightly narrower diameter than the originals so the switch gear and throttle tube clamp may have to be shimmed a little bit.
Thanks for the straightening tips Scorpio,

sadly the bar actually snapped clean in half which makes me think it had probably been weakened before.
Oh well...you live and learn eh?