“CORK AS SHOWN BEFORE SHIPPING” plate for a marine chronometer is an original New Old Stock brass plate that dates from during WWII and was made as specified by the US Navy Ship’s Chronometer Record Book (Form N.B.S. 702) Transportation Paragraph 2(A) as referenced on the plate.
It was probably made for the Elgin National Watch Company that designed a marine chronometer for the Navy but was unable to get it into production and have it accepted.
It is suitable to be used in any marine chronometer and still makes a great reminder!
It is made of brass in the 1940s and was never used.
It measures 2 1/2 x 1 1/4 inches and was designed to be attached inside a Marine Chronometer box to remind one how to properly immobilize the balance wheel before transport. It is shown next to a U.S. quarter for size comparison.
The pictures show it next to the US Navy book with an excerpt showing a simlar plate. Book or chronometer not included.