Hi Ric. From the information I have acquired over the years, Newport Motor Yacht built a number of wood boats to Seeley's designs, most in Japan from 1969 to 1972. I have heard of at least 3 boats in the 48' range, and maybe 8 boats or so around 38'.
I have been onboard a wood North Sea 38, and it is very similar to the fiberglass Pacific Trawler 37, with slightly less beam. In 1973, Pacific Trawler Corp started building Pacific Trawler 37's from a mold at Costa Mesa, CA. Although some of the early literature hinted at a 47' model, I don't believe that any fiberglass 47's were ever built.
Pacific Trawler Corp built around 20 37's in California from 1973 to 1976 before going out of business. A single 37 was built in 1979 in Marysville, WA, and a new Pacific Trawler Corp started building from the original 37' mold in 1996 through 2003 in Bellingham/Laconner after a run of around 35 boats. Some of the later boats were pushed out to 40'.
Maybe others can comment if they have heard of, or seen, other North Sea 47's. J