[willy]

I would find out who did the stringers first, ask for pics and post em. There are right ways and wrong ways to do it and guys here will tell you right away.
Also, when stringers are bad enough to be replaced often the transom is soft too. Not always, as Wellcraft was notorious for not finishing the holes they drilled through them to allow drainage so a lot depends on long they were soaking away. Also, were the whole stringers replaced or just a small area where the motor mounts are located, which is also common on inboard engine mounts.
I owned a 92 and it was a great boat but I think you are paying too much for the boat if you stay near the asking price.
I hear your concern for the closed transom which I also liked but the design on the Wellcrafts was pretty good at keeping water out, especially with that late of year as Wellcraft raised the floor almost two inches starting around 1998 for better function of the floor scuppers for any water that comes over board. And unless you over weighted the stern with a too heavy motor which some do it is a very dry boat pretty much all years. After a certain year I believe was around mid 80's they all had a wall around the motor well which kept any water from splashing on board from the stern.
As far as that center counsel posted it looks nice but it appears they cut down the transom to run a 20" shaft motor for some reason. I don't know why.