You mentioned that there were no filings around the screen on the oil pump, but the place to find metal detritus on a CB72/77 is in the centrifugal filter you exposed in the clutch housing. If you pop the circlip and remove the front plate, you will probably find a felt like lining in the body of that oil filter. That "felt " lining is all the small metal shavings that the filter has caught since it was cleaned last. I wish that I still had my old CB72, you're bringing back some old memories of mis-spent youth;-)
Excellent advice, thank you 'Rope! I wish I could proudly declare that I've got the bike shiny and complete, but I've been too busy riding ADV and DS motorcycles and working to spend quality time finishing her up. All I really need to do is reassemble the speedo head, electricals and bolt on some replacement parts. Winter is coming, so maybe that'll give me the time I need!
