I know it’s a very old thread but I had never seen that section before, I guess this is new.
I have put that question to my current boat’s first owner, a qualified and experienced Grand Banks boats’ owner. I quote his reply.
«She is an Admiralty, a line of motorsailer yachts built by American Marine Hong Kong Ltd in the late 50s & early 60s.
In the late 50s many years before the launch of Spray in 1963 which introduced the Grand Banks line, American Marine Ltd was already famous for building custom boats, heavy sailboats and motor-yachts. There was the Chantyman line - a 35’ pilothouse motorboat - , the Admiralty line - a 50’ motorsailer designed by Roger Mac Aleer - , and a 40’ sailboat designed by Sparkman & Stevens. »