It is too far gone for the plastic liners to save it. I have re-chambered square balers. I have a local metal shop bend a new metal chamber and the cut out the old one. Then install the "new" piece. I usually take part of the old one to the metal shop so they can match the bends. You usually just need to do the front half. The metal does not cost that much, $200-300. It just takes a lot of time. If you are a good welder and can get it real cheap. You could fix it for a cheap baler to use. It would not resale for much though.
If you are not up for that big of a project then if it is cheap buy it for a parts baler. If it is a New Holland then most of the knotter parts would work on many different models. I have several JD and NH balers that I bought for parts. They have saved me a lot on repairs. Those new knotter parts are getting quite high. I just take the salvage part and blast it in a small balsting cabinet I have. Makes them look like new.