I own a small boat that I have assumed was an early FJ, but am not sure. It is plywood over mahogany ribs with mahogany transom. The overall length is 13'6", beam is 5'2", and mast is Douglas fir with a height of 18'4" above deck. Sail markings are J 527. Also, it has a fixed keel with lead ballast, which may have been added. Any ideas as to what it is?