US M1 Helmet question

[Jammanna]

Hi folks, I've been collecting M1 helmets for a few years now so in my opinion I'm about half way to where i should be due to lack of study. I came across this M1 helmet that's got me baffled as to why it would be the way it is. Its the shallow M1 rear seam swivel bail, (When did they go to the shallower shell) It has a nice patina to it. I can clearly see the letter S inside the front rim of the shell. Whats got me confused is the sewn on chin straps. Even more so is the wear to the straps. I know stuff can go through altering hands in their life spans but why would someone go through the trouble of sewing them on. Any thoughts

[ruddersrangers44]

Hi what makes you think its a shallow shell type?it a ww2 rear seam Schlueter pot if its got a "S" stamped near the front visor,keep at it friend.......

[plumbob]

Hi its Schlueter helmet you have there, I haven’t got one but apparently they are more flatter around the rim than an McCord which is more curvy if that’s the correct word (if thats what you mean by shallower) . These would all have sewn on chinstraps as far as I am aware .
rod

[Jammanna]

Ok heres the difference...granted the pot on the left is stamped 647B. The difference is 5/16". I have heard what your saying about different profiles from one manufacturer to another but this seems like a pretty big difference. I did purchase this helmet with a 100% correct ww2 liner.