Looks like a nice mid to late war front seam swivil bale lid. Liner may be a little older.
Look in the very top in the liner and there will be a makers mark. See if you can get a close picture of it.
I do not have a clue about the decals though. A good WWII model.
Oh yea. It isn't camoflage. Just worn in spots.
I am guessing that the owner was a private first class in the 28th infantry division, judging by the keystone decal on the front of the liner. It looks to me like maybe it was used post-war. I could be wrong, though. I'm no expert on these.
Looking for WWII U.S. dog tags
The division on the front is 28th infantry division, the side is the 28th infantry division crest and its without a doubt 110% ww2 because on the liner its has a the guys serial number and i looked on the archives and it said he enlisted in 1941 and i think the helmet has a camo if you look at other helmets from the time theres camo like it. - Nick K