This is an original WWII leather liner strap. It features United Carr stamped blackened brass rivets. The leather is still quite soft and supple. The underside of the blackened brass buckle exhibits the rare patent number of 2363872, dating the strap's production to November 28, 1944. This would be an ideal strap for high-pressure helmet liners with blackened brass A-washers.
WWII Leather Liner Strap With Black Brass Buckle