You can slow the rot around the hole if you chuck up an allen wrench in a drill that you can hang on to and chew the wood back between the glass and then fill it with a PB..
I would give him the benefit of the doubt but certainly get in touch with him.. may have had a couple of boats for sale and got mixed up..if so he will be glad to hear from you..
I've used rector seal on my well fittings, it's a good pipe dope. I only have about 40lb of pressure so can't say how it works on city type pressure..
Enjoy your chicken!
I opened up a 1978 220 cc scorpion and it was a grid.. I gutted it and put some decent stringers in it, did not replace the half-ass bulkheads .. I enjoyed the boat for 20 years after...