This is a Keystone C-12 Aircraft Carrier model #219. It measures 15.5″ x 4″. This ship is an example of the C-12 produced after 1942. It is identical to those made prior to 1942 with the exception of a loss of one plane. All C-12 aircraft carriers had two planes and two plane berths in the hull. In 1942 they went to one likely due to the increased demand for metals for the war effort.
From my private collection.