I'd leave that one well alone, if I were you.
I see an M15 liner, a correct Baden enlisted men's wappen, but also a fake officers Prussian kokarde, no kokarde on the left, a rear spine not fitted well, a not correct artillery kugel, look at the base of it! Also no ventilation holes in the base, like there should be.. A fake chinstrap, and a strange hole, which should not be there, visible on the picture of the inside of the helmet. That hole was plugged up,and probably just behind the head of the Baden wappen, which is correct, that wappen. No spike supportdisc. It might have been a helmet which was made to look like a military pickelhaube, maybe it was once a civilian, or firefightershelmet, but I don't think so. A firefightershelmet has more holes, and I don't see them here, only the one in the front. Also no depression of the comb visible on the outside. Which you can normally see when a firefighter helmet was converted into a military pickelhaube.
All in all, I wouldn't touch it with a 10foot bargepole.