'Mitch' - The picture of your new Krag's muzzle is kind of busy with the lead residue and finish wear. I am not totally sure of where the top of the barrel is. If there is a groove across the top of the barrel, it was made later by whoever put the 1903 banded sight on, for the 'cross-pin'.

If a Krag front-sight base was cut down and filed flush to match the barrel contour, the brazed dovetail seam would be pretty discrete and hard to see.

FWIW - Clean off the Lead and any surface corrosion & look very carefully for the remains of a fine brazing seam.

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