Well, I picked up a '76 last fall and now after I've got my '80's oil changed, paper filter upgrade, LED headlight upgraded, and new sprockets and chain done using a 32T rear and 17T (stock) front sprockets, and rear brake free play adjusted, I could start on the '76. I got it on the lift and hooked up a battery and the starter button was stuck and would not operate. Pulled that all apart and cleaned and straightened the little cage the button and spring are housed in and got that to work. Hit the button and the starter just spun. Drained the oil and pulled the right side cover off, hit the button and the starter gear now engages. WTF. Anyway, pulled the clutch apart and found the fiber plates under spec (.115" - .117" - spec is .122" min.) Ordered new plates, new spring bolts, new upgraded thrust bearing, new one-piece pushrod (the old 3-piece one was in backwards), new pushrod seal and new pushrod bushing. Also found spacers and washers were installed in and behind the clutch in the wrong places. No lock tab washer for the nut, so I ordered that too.
I'm in the house eating lunch right now and when I go back out to the garage, the sump cover is coming off and I just KNOW I'll find the intake screen ripped. I also have to get the bolt out for the right filter cover, as it's stripped out right now. The handlebars on it now are ape hangers, so those are coming off and I have handlebars from an XS400 I parted out and scrapped that I'll use. I believe they are the same part. After that, it's time to check the alternator brushes, the points, and pull the carbs for cleaning/rebuild.
Edit 45 min later: I hate to say I told you so, but...
So now I order one - should I pay $48 to Mike'sXS and get it in a few days, or pay $31 on Amazon and get in in freakin' September? $48 it is.