I think the biggest tell on this helmet is that it is made from an Austrian helmet, the Cav, helmet was made from the M1918 pattern, and the chinstrap bails are attached to the liner band, not to the helmet shell as the Austrian model was.
Bet
Gus
Okay, this was done by placing a standard helmet on a stake and re-forming the lip or rim. You can see the wear marks from the stake on the side of the helmet.
Yes, 100% fake.