German / Austrian Duckbill M33 Police Helmet
You would be forgiven for thinking that this helmet was a German First World War Stalhhelm. Its design was indeed copied from the M1917 however it is made from lighter metal and features a similar leather liner to WW2 German combat helmets. The black paint and pepper pot airvents are a giveaway to it being a wartime police helmet.
Part of the chinstrap is missing.