1977 prototype Scrimshaw Zippo with The Outrigger design on genuine ivory.  The reverse was also made of ivory but was not engraved.

Scrimshaw is the art of carving designs on whalebone or whale ivory.  Scrimshaw Zippos were test marketed in 1976-77 in three designs:  the Outrigger, the Schooner, and the Whaler.  Zippo found that "genuine" scrimshaw was too expensive for the average customer and in 1982 introduced scrimshaw designs on cases made of acrylic materials rather than ivory. These remain popular today, with a variety of attractive maritime-related designs featuring  lighthouses and sailing ships. Genuine scrimshaw Zippos are rare.

Scrimshaw Zippos

This scrimshaw design on genuine ivory is the Schooner and is also dated 1977.