Just so you know, most plumbers would have slammed in a new single handle and been done with it.
Yes. And I should clarify that I found a second plumber that actually got the seat out. I bought the #6 Easy Out and told him it had been suggested as a way to get it out. I am sure he was already was aware of that method. Anyway, he used that and my socket wrench extension to make it reach and had to put a
lot of force into it to get the seat out (I had been very hesitant to put that much force on it as I was afraid I would just make things even worse than I had already made them).
He had also suggested the single handle route but indicated a lot of people don't like to do that, and I am certainly one of them. The first plumber I had come out also suggested the single handle method and did not want to do anything other than that.
Hopefully a replacement seat can be found. If so, I will have saved quite a few dollars, learned quite a bit, and have the separate hot and cold handles that I prefer. Apparently I may be one of the few people that prefers this though.
Slowly making progress. Thanks again.