i have some outer clutch covers from various bikes, and have about 6 500 side covers for my 3 bikes. i was going to make a 2 peice job when i built my 86, but just trying to weld the crack i had was a mother. the old kawasaki aluminum parts seem to be made from junky metal. when you wled on it it is like it was covered in crud and you just started burning away, but my part was spotless, mek'd the whole deal. i had to fix a bunch of stuff on my 86 cases, half the clutch actuator was gone, and lower chain guard tab gone. the metal there was not too bad. but my clutch cover was a pain.
i have some 90s era covers, one is pretty trashed, so not too worried if i kill it. was thinking i might give it a go soon. i have never liked taking the whole side off to mess with the clutch. it looks like the later aluminum wasn't so terrible.