U.S. WWII-era commercial M1917 helmet, repainted and used as a Homefront police helmet during the war. I have not been able to find much on anything similar, so any info would be
Haversack - Wikipedia
Opening Moves: Marines Gear Up For War (The Stage is Set)
Helmet, Protective, Type M1917, U.S. Army, American Rocket Society | National Air and Space Museum
File:91ID M1917 Helmet.jpg - Wikipedia
M1917A1 “Kelly” Helmet - Eastern Costume
M17 U.S. Brodie Helmet | Historic Aviation - The #1 Source For High Quality Airplane Collectibles And More
World War One Doughboy Helmet] - UNT Digital Library