Sorry to dredge up an old thread, but I just bought an 18 foot Queen Merrie. I think it is at least a 1962 since it has the 76" beam, but I couldn't find the number on the transom knee brace like the OP. It looks all original, from the airguide gauges to the original cubby storage units behind the front seats, so any idea where I would look for the ID Number?