Carb rebuild with new jets, fuel line and filters and a fresh battery and she came back to life.
I think the jetting still needs a bit of tweaking, but the airbox boot is in a bad way and hard, making it a real pain to get on and sealed, so I'll likely go with a quality set of uni filters, so I won't mess much with the jetting until then. The petcock is still leaking like a garden hose as well, but in leu of another rebuild, I plan to adapt a manual petcock and be done with this vacuum operated unit once and for all.
It needs a deep clean as well, but still a handsome looking bike imho.