Unknown m1 helmet heat stamp

[Joogie]

Hello,
I Recently Bought An M1 Helmet Off of EBay, And While I Was Sanding It, I Found The Heat Stamp..! But It Looked Odd since it was only numbers and no letters, as far as I can see, so can anyone help me determine if it is a ww2 or post war helmet? Thanks.

[Joogie]

If you can’t read, it says “463” it is a rear seam, and swivel baled

[MedicalAmmunitionCrate]

Could possibly be an European clone of some sort. The picture is pending approval on my end currently..

[Joogie]

Possibly, I hope not though, lol