The NSR muffler should arrive next week, so I'll see how that works out. Thanks Lozza!
Hey Tex :-) Yeah, the KTM option sounds good. If you have one spare, send it up!
I've found a mangled ball of 'something' blocked the std muffler - could be the remnants of the chamber washer thingy by the looks of it.
The RGV (suggested by Doc originally) I'm using right now is an early solid one, not a late unobtainium thing. Works fairly well, but is pretty hefty.
So now I'll compare results with the std, std-packed, RGV, NSR and maybe a KTM if I can find one.
Thanks guys!
Luke