Original WW2 US Army M1 Combat Helmet - Swivel Bail - Front Seam
LINER:WESTINGHOUSE ELECTRIC COMPANY
In 1944, the stainless steel helmet rim with a seam at the front was replaced by a manganese steel rim with a rear seam, as well as the helmet bails being changed from a fixed, welded version to a swivel model in 1942, along with slight alterations to the shaping of the side brim. 
 LINER:WESTINGHOUSE ELECTRIC COMPANY
 Manufactured in Pittsburgh, Pennsylvannia this "high pressure" manufactured M-1 helmet liner is identified by an embossed "W" in the crown (which is still Westinghouse's logo to this day).  Westinghouse was the largest M-1 helmet liner producer and had two production divisions; Micarta and Bryant Electric. The Micarta Division produced about 13,000,000 M-1 helmet liners and the Bryant Electric Division about 10,000,000. Westinghouse Electric Company started M-1 helmet liner delivery in May 1942.  Westinghouse did have a contract to producce airborne liners and converted an unknown amount to airborne configuration.  Westinghouse discontinued production around August 17, 1945 when the war ended.