Letters and Numbers on an Army Helmet Liner?

by Subit0Forte

So I recently came into possession of a Cold War Era M1 helmet. The liner of said helmet has three markings on it all in white paint: Front: A Right-side: 13 Back: 3

What does ANY of that mean?

Mackinturk

Do you have a photo? Are the markings inside or outside? Are they only on the liner?

I used to work for a military headgear museum. From the sound of it, they're probably some sort of unit or inventory markings.