'Flatlander15' - The "hieroglyphics" on Krag Bolts, Buttplates, Magazine-Gates, and Receivers are believed to indicate inspections that followed various manufacturing steps. The exact meaning is probably no longer known.

The original model 1892 Butt-Plate was flat. The Butt-Plate 're-curve', at the stock 'toe', likely came as a result of 'flat Butt-Plate stocks' being prone to splitting, when rifles were sharply placed at "Order Arms".

A cut of wood has been taken off of your Krag's (altered model 1898 stock) in order to fit the plastic butt-plate.

It would be a bit of a waste to try and use an original 'Flat Butt-Plate' or a good later Krag butt-plate on this stock. It would require a lot of wood and metal shaping for it to look right.

I would use this stock, as is, or find a 'junk -altered' Krag butt-plate that comes close and 'flatten' the re-curve.

(There are a lot of 'altered' Krag butt-plates, that were narrowed for 'sportered' stocks. You have the plastic butt-plate as a guide).

The fit of your barrel and receiver look correct.