Original U.S. WWII Manhattan Project A Bomb Workers Pin - Sterling Silver Technical Books It has both Hitsu-ana (accessory

It has both Hitsu-ana (accessory holes) for both the Kozuka (kogatana handle) and kogai (hair ornament)

system patented in 1823 by JOHN DAY

These modifications resulted in the M1862 Metalhelme

and another tiny one at the front of the lock plate

in that it has a

Original U.S. WWII Manhattan Project A Bomb Workers Pin - Sterling Silver Technical Books It has both Hitsu-ana (accessoryOriginal item: Only One Available. This is a genuine sterling silver MANHATTAN PROJECT pin that was given to the workers who spent for more than one year on the project. The pin is in very good condition with working pin and catch. It is nicely marked on the reverse with maker Whitehead Hoag and Sterling. Pin measures 11 16 of inch round. It comes in a small display box, but we do not know if this an original box, or just one used to store it. The