Looks like a good and fun project to restore, best wishes to you with it.
I saw it when it was available, and it looks like it has Depot issue markings originally to the 14th Infantry Regiment on the underside of the back visor. (14 J.R. is stamped into the leather.) I'll post a photo of the marking.
Are there extra holes for a regular Prussian line eagle front plate in the forehead area of the helmet?
The helmet cleaned up well and I was able to find the parts needed for repair. It looks good with my M1915’s. Thanks to everyone for the positive encouragement.