Hi Gordon,
Good to have you aboard.
Yes, I believe your boat is the last factory-built SeaHawk, but not the last boat. See:
http://www.seahawk17.org.uk/history/index.htm#nextdecadeHowever, it is just possible that further SeaHawks will be built. A couple of years ago I was approached by an experienced boat builder who had been in contact with John Bennett about resuming production and asking me for advice about buying an old boat with the intention of creating new mould tools from it.
He later sent me photos of the boat he had bought that was, by then, in a partially stripped down state. I really should attempt to contact him again to see what became of that project.