I’m in NH looking to replace these seats without having to drill new holes and Love the flip down and lift up exposing the built in bench. Any ideas as where to get something like this?

I just always make mine, it's not and overly difficult job to do.  I would think most any upholstery shop that does boat seat could make you some.  However, they are so uncomfortable, when I can, I usually swap them out for some of the newer molded to fit seats.

Try Llebroc.  I used to have them make mine.