Need Help Identifying this Stock

[Rogue5]

A good friend handed this M2 Type 5 Carbine Stock.

It has the Selector cut out, Pot belly but no marking anywhere that I could find, except this "S" mark on the inside front right part of the stock next to where the top cover would sit.

In addition the stock has 3 holes at the butt stock (one Large beveled at the center, and 2 smaller holes (top and bottom) where a butt plate would go.

[Rogue5]

Marking possibly Springfield Armory
Based on this Online Article: The U.S. Caliber .30 Carbine Stocks & Handguards (uscarbinecal30.com)

[countyman]

I read, from one of my Carbine collector books, that "S" marked stocks, on the top edge under the hand guard, were Springfield Armory manufactured replacement stocks. I'll try to find the reference and post it.