Most folks will advise you to steer clear. There are zero parts available for that gun.
But, if the price is GREAT, and it is in excellent shape, and you have no intention of short-stroking it or slicking it up, and you want it for plinking or light duty, well, it might be okay. On the other hand, I've shot my 2000-vintage '66 almost ten thousand times (all stock parts) in CAS and never had a failed part, so maybe the old carbine has some life in it?
Personally, if it was in good shape I would buy it only if it was cheap enough that I wouldn't be too upset if it became a wall-hanger.