I am looking to fix my old original PS1 to sell off along with many games, but the small clips that hold the disc in place when you push it down have broken off (3 of the four). Sometimes games will play, other times it won't. I think that's what's causing the problem. Or could it be a worn lens. Tha part that holds the disc, is that available and if so, is it cheap and worth reparing? Same goes for the lens.

Any advice is greatly appreciated.