Z500 for 500

Hi Gents,
have been looking for a while for a z650 to add to the stable (hard to find in WA) but a cheap 1980 z500 has come up as a fixer, I know these had cam chain and tensioner problems but my question is are they worth doing up?
cheers
DJ
have been looking for a while for a z650 to add to the stable (hard to find in WA) but a cheap 1980 z500 has come up as a fixer, I know these had cam chain and tensioner problems but my question is are they worth doing up?
cheers
DJ