Some insurance companies won't allow a "buy-back". They say they are under contract with a salvage company, and it's not up for further discussion.
That said, the Elkhart Ind. area is one of the biggest pontoon manufacturing areas there are in the country. I would think that if that's not too far, you might want to do some poking around there. If the right welder fixes your project, I would have no trouble trusting the repair for the life of the boat.
Last thought, when it comes to boat upholstery, unless it's been carefully covered when not in use, and stored indoors off season, that vinyl is getting to the age where it's going to start showing it's age soon, no matter how careful you are with it. Having it redone, and replacing the carpet to reset the clock, could be about what you've paid for the boat....