There were/are 2 types of the 'Potbelly' stocks.
Yours looks to be the early first style.
This picture has a early style on top. M marked slingwell. Flat bottom profile common to this particular maker.
2nd style below, showing a more pronounced bottom profile, a HI stock.
I can't explain the CC stamp on yours.
Wood looks like a light walnut, but birch can fool me at times. Normally a Birch will show a whiter ring around the pistol grip.
Either way it looks like you have a nice set up for range time.
I could be happy just collecting the wood!
Cheers

Charlie-Painter777