Reminds me when we were at the tanker monument being built near Cambrai, and they were clearing the brush near a low stone wall. At the base of the wall, buried under ages of natural debris and current growing wild grass and weeds, was a WW1 German grenade, still live. That was an uh-oh walk away moment....
Welcome to the forum, a sad and sorry tale for sure but you will not be the first or last to be duped by the "bay fakers". That really is a one looker fake SS helmet. At least you have found this fine forum with some real experts who are only to willing to help a serious collector who is ready to learn. My knowledge on all sorts of mlitaria has improved in the few years I have been here, plus I have made some very good friends. Enjoy! Leon.
"Always do sober what you said you'd do drunk. That will teach you to keep your mouth shut." Ernest Hemingway