Nice score Frosty! I'd be sending that later model front guard off to the salt-mines though!
I believe that all of the case-reed, LHS kick-starter KTM125 motors (83~91, IIRC?) will fit, but really don't know for sure.
I've got an 89 125GS motor in bits. It isn't complete enough to use as a rebuilder (and I want to keep it as spares for my 89) but if there's any bits you need, then just ask.
I also owe you a PM about TS stuff...