Chrome in such mass has not been seen since the Buicks of the late 1950s!
The leather straps are dyed white.
The shell is marked U.S. Naval Training Center, San Diego (California). This is what really caught my eye when I first saw this lid as I (and zillions of others) am an alum of that august institution by the sea. I attended boot camp at the Recruit Training Command of NTC San Diego as well as Radioman school and teletype repair school.
The purpose of the two grommets is unknown to me. But the grommets represent only the beginning of the chain of mysteries.
The Korean-war era liner interior is complete and quite clean...
with a crisp Firestone logo in the dome.
Both the headband...
and the neckband are marked and somewhat legible.
The butting and spot-welding of the front rim seam are crisp and neatly done.
The custom chinstrap fastens to the interior of the headband with two-position snaps.
And is further adjusted with sliding buckles.
As with nearly all of my Navy M1s this helmet is stamped with the Schleuter "S".
A close-up of one of the mystery grommets. I doubt that these were for ventilation, nor do I think they were to support any screw-back or wire-back insignia (as the insignia is stenciled on). Its a puzzle.
This helmet was part of the regalia of the Recruit Training Command precision drill team, note its leader about to be bayonetted below:
Sadly, NTC San Diego was disestablished several years ago with the end of the Cold War and the absence of the Soviet Union as a credible threat and the widespread acceptance of peace, love, justice, brotherhood, and understanding throughout the world.