Cold Molded Plywood
Cold molded plywood boats were made with multiple layers of diagonally placed thin sheets of wood veneer, glued together and vacuum sealed in a plastic bag until the glue was set. The hulls of these boats are often in quite good condition because they are effectively one piece construction.
1957 North American Marine 14' Runabout
The photos below show the before, during, and after restoration of a cold molded boat. In this case the boat was painted by a previous owner which actually protected the mahogany plywood from the elements. After stripping the old paint the boat was stained and varnished to its original condition.