Spooky, stick with the HD Aermacchi every time, proven bit of kit, reliable if not 'tuned' too far, still raced, so spares are available and a slim lightweight design to boot!

Why part with the 'macchi for a sleeved down, underpowered, poor spare parts availability, overweight, under braked, Sanglas that handles like a barge in a Force10?
You'd probably be better off going and buying an AJS/Matchy 350 unit motor, at least they can be made to run reliably, have a bit of 'pep' and spares are relatively cheap and plentiful. They also look similar to the Sanglas in their original bodywork, if that is what is catching your eye.
If you decide to flog the 'macchi, erm, a PM, please.

Regards, Bill