yes, it appears to be based on the civil war helmets of the roundhead cavalry from the english civil war,
the q. is if it's a period one or a repro. the ones i've seen could be worn, the bill woud have been horizontal, the ear pieces hinged and tied under the chin, and the rear neck protecter would hang down the neck, and be articulated similar to a japanese samurai's to allow for some movement. these would have been worn for hours on end, marching and fighting so some balance, comfort and flexibility were required.
a wall hanger would not need to be as critically made. if you can't wear it and move around in some comfort with it not trying to fall off at the slightest movement, it is likely not period, but designed to grace the walls of a victorian lord's mansion. repro's tend to be made from lighter sheet metal rather than hand forged as well.
playing devil's advocate, their were lots of variants as these could also be made locally by the roundhead village smithy who was trying more to make it look like he thought it should be than the army would have liked, but as in all low bidder supply systems, it's the trooper at the end of the supply chain that gets stuck with the simplified 'variant'.
here's a three-bar type, note the bill is hinged to allow it to be raised and note the ear pieces. this is a repro.
a helmet similar to post 1's.
