So after the steering head bearing change (thanks to adv forum member bwringer,) the bike is generally rideable. Turns out that I did bend the disc trying to change the tire, but bwringer had a couple off a GS850 that fit.
Tried the correct one for the left side, but this one appears to have been the reason he took them off his bike. Pulsates under braking, so I'll take it off and put the one for the right side on the 850 on the left side. The holes in the disc will look odd, but considering the cost of the discs...I'll ride with it looking a bit odd.
The road test in '83 said their test bike really benefited from a sprocket change and I can see why they decided to change them. Just feels like it is running too hard to achieve 60-65 with the stock sprockets. Something to work on over the winter.
I intend to ride it for now while the weather is good and enjoy the results of a summer spent trying to get it to this point.