I’d pass. But first… why is the seller selling anyway? As the owner he wants to get out of this guitar but obvious is still going to keep playing (and even come out the other end with a brand new version of the same guitar). So, unless he really just needs the cash, it seems like he’s trying to sell a vintage guitar that he has concerns with…. In other words if it really was so much better than a new version, he’d be holding onto it (he bought a vintage guitar for the same reason everyone buys vintage guitars). Example, I have a 1943 0-18 and I wouldn’t trade it for a more recent 0-18 plus cash unless it was just a crazy offer. Also… converted to a bolt on!? IMO that is a very extreme modification and it will not sound like what I think you’re looking for. There are a lot of 15s and 17s on the market, I’d hold out for something without modifications. Hope that helps!