In need of assistance from someone who has more knowledge then I do, or calibration. I have a front seam, fixed bail M1 helmet, in good condition. lot number 272 (no letter) and 126 (on the inside of the brim), and has early war chin strap. The liner is Seaman Paper Co. and in excellent condition as well. Note: the netting and sweatband are reproduction. I was wondering if someone can give me some intel on what exactly I have. I have done some research but a lot of answers (if you know what I mean). this helmet is Depth: 7 in. Width: 9.5 in. Length: 11 in. Helmet shell and liner came together both in OD#3. i've attached photos for you all.