Nice checkering. I think it is post-war, either a Bishop or Fajen stock. The bolt stop is from a Steyr,

make sure that it is a broken screw and not a broken tap.

As to checking out whether it is a 30-06, try chambering
an empty cartridge. If it chambers, good, then put some
inletting black on the shoulder of the chamber, try feeding
the empty cartridge from the magazine into the chamber, close
the bolt and then open the bolt and eject the cartridge. Look
and see if the inletting black has been transferred to the shoulder of the cartridge. Check to see how far a 30-06 bullet
goes into the muzzle.