the rust appears new,the bullet hole is in the near top off the rear and comes out front edge.all very strange.
Has the crimp score line typical of ET.
Alot of different possibilites, only the imagination sets the limit.
I rather stick to the theory it is an post45 added damage, done some time ago before these items become very valuable just to speculate on the value and make some money on a rusty helmet.
Collect ROA, Cossack, Schuma and other WW2 Volunteer militaria.
"Be Humble and kind, for you may find that it was Odin you entertained"
Entry upper-left backside, leaving front right.
The hole has the diameter of the M-1 carbine ammo.
The region it was found in - WAIMES - (where it was stocked in a garage for 70 odd years) was the scene of house to house fighting with shooters on al floors.