These helmets were introduced before ww2 so just after the great war in 1921 ,well done on identifiying the model type as the m21/16 is hard to tell apart to the novice collector ,have you had it in storage as its in remarkable condition especially the liner pads and chinstrap showing little wear here in the uk i would expect it to go from anywhere between £50 to £100 ,usually they are bought for the liner alone to refurbish the early german stahlhelm's
Bought it for next to nothing from a collector with some financial issues about 5 years ago. It contained a swedish newspaper from 1944 so I guess it's been in storage for some time. I've researched it for some time and concluded that it had to be the m21/16 model. I've seen them on Ebay, but their condition is much worse then mine. I also bought a Canteen from him marked USA 1942-1944, but these seem to be pretty common and not of any value. Thanks for the great help and informtion James, appreciate it!
your welcome and hope more member's here add there thoughts too
Very nice and uncommon helmet that I haven't seen often and thanks for posting it