I am looking at buying a house with an in ground pool with a liner. Part of the purchase agreement was that the seller had to repair the sagging liner. The first 2 pool guys that looked at the liner said that there was 2 pieces of track missing and that due to the liners age (about 7 years), and being somewhat brittle from extensive direct sun due to the pool being not completely full, (about a foot) you would have to replace the entire liner when replacing the track. They said I would have to unhang the liner and replace the entire track, that you can not splice it in. The track is not metal, but they both recommended replacing the track with an aluminum one. There has now been a third guy that has went out and he repaired the sagging, but I can not get a hold of him to see what he did about the track. It looks like he used small pieces of liner lock to fix it, maybe 10 inches long. He did not put the liner lock on the entire pool. The liner now bulges slightly in the 2 repaired places. All three pool guys were professional pool guys. I don't know if it matters but the pool is saltwater. So I guess my questions are

Does this sound like a reasonable fix?
Can you splice in track?
How long should I expect this type of repair to work?

I would post pics of the work but I am not allowed to. I am open to any and all advice. Thank you in advance.