Back in the 1960's, Herters offered rough stock blanks for most surplus arms. The 'notch' on the left-side of your stock was probably intended for the Kragicon's Magazine Cut-Off Lever.

The Krag barrel does 'lift' upon firing and a lot of torque is transferred to stock's 'action-area'. Because your stock partially covers the side-plate, it is a bit stronger (than a U.S. Krag stock).

A barrel-band or improvised forearm screw keeps the Krag barrel in the channel where it belongs.