Yah, more photos!

Krag, #68900, is a "SRS hit". Frank Mallory documented it as a model 1896 carbine, turned in by the 6th Cavalry, 04/11/1900.

I have never seen a 'staple' attached to a Krag side-plate before. Almost certainly, this was done by or for a private owner.

What type of stock is on this Krag now?

The original model 1896 carbine stock would have had a carbine ring & bar on a plate at the stock wrist, just behind the magazine cut-off lever.

BTW - A replacement side-plate will need to be for the model 1896 action. The model 1898 side-plate is too thick to fit at the front 'tendon'.