Looks like it could be a great bike with a little TLC. Why not just replace the plastic bushings with needle roller bearings if that is a concern?
It should be an easy fix.
Eric
If you can find some that fit correctly, it would work for a while, at least. I don't think there is ANY way to lube the bushings-bearings on that particular bike: at least I never saw any way on the 1979-1980 models that I remember. There were not zerks, bolt holes, nothing! The articles I remember reading about it mentioned disassembly and hand-lube as the 'fix', much like the old BSA twins.
With the needle-bearing kits, the hard part is in finding some that are properly made to fit the arms. I've removed a fair amount of them (or what was left of them) from the SOHC4 arms after the attempt was made to install them and failed. Either the needle cage was too large, causing it to crush during install, or too small, causing it to slide in and be quite loose after the "rebuild" was accomplished. So far, that's the only way I have seen the needle bearing kits in my own hands?