I obtained the critical parts from PentonParts (thanks Alan, for having them!), so #2 Son basically did the remaining tear down of the main frame while I was working on a commisioned job.
While we were doing the forks, I noticed that the rubber o-ring had broken (dried out, whatever the case) and saw the bearings visible - I trust this is normal? I would have thought the bearings for the steering head would have been better sealed. Strangely enough, the movement of the forks left/right was smooth enough - but I think I'd look into replacing them when I get to servicing the forks and seals.
I also found that one of the clutch actuator/cover capscrews had been stripped out once apon a time, so after taking a closer look found that the threads extend right into the transmission cavity, so any thread tapping is going to put metal into the gear set. Not good. so I figured I'd pull that side of the engine housing off. Turns out the sprocket output shaft seal took a hit and is deformed, so have to add a seal for that, gasket for the housing and a seal for the end of the crankshaft too...PentonParts to the phone please... one of the machine screws that holds the ignition system to the crankshaft cover sheared off too - sigh. Better take an inventory on what small drill bits I have available.
There were some previously repaired cracks that need to be cleaned up and I wanted to get the frame cleaned and painted, so in the event the engine comes together nicely, I can basically continue with the rest of the restoration without having to pull the engine off again.