Unit marking stencil on M! chinstrap ?

[3FDWKSP]

Greetings from Arizona -

Have a question for those much more knowledgable than I - and I will thank all in advance.

I have a M1 that has the following stenciled on the chinstrap - looks like 39 HQ 66 then following 3 - 10A - D -14 .
Also it is finely painted in the inside - 39 HQ 66 - all this over a re-paint over the white letters of the US number and the mans last name - Korea?

I am still working on the learning curve of posting photos - it would be more helpful I realize. I thought the unit #'s might ring a bell with someone.

Cheers - 3FdWksp

[MAP]

This guide may help regarding uploading photos. Always best to upload from a PC. Often times uploading from Cell phones results in sideways / upside down photos.

Visual Guide to Upload Photos