I did not take the cover off beyond what you can see in the photos. The cover is dated 1953. I think the liner is an International Molded Plastics as the maker mark is an oblong circle and I cant really make out what is in.
But I dont think it is an S for Seaman Paper. The liner is in good shape with a small rough spot on the edge at the very rear but otherwise it. To be in solid shape. The liner has good webbing.The chinstraps are in very nice shape. The steel pot feels like there arent any major dents or. But I didnt take the cover off completely so I was limited to feeling it through the cover and seeing the exposed parts when I had the liner out. I did peel back the front ear of the cover to see that the shell is a front seam and that the paint appears to be original and in good shape.
The cover is in good shape as well and has a cool inked sergeant stripe on the front. I have no information on Sgt. The item "WWII, Korean War 1953 USMC M-1 Helmet with HBT Camouflage Cover, Named" is in sale since Saturday, April 27, 2019. This item is in the category "Collectibles\Militaria\WW II (1939-45)\Original Period Items\United States\Field Gear, Equipment". The seller is "azamy" and is located in Glendale, Arizona.
This item can be shipped to United States, Canada, Bahamas, Uruguay.