FWIW - It appears the silver-solder joint was strong enough for our purposes.

IMHO - The S&S front-sight base would give a better appearance if the 'flange and dove-tail' idea was dispensed with.
The bottom of the sight base could be ground 'concave' to match the radius of the Krag barrel, near the muzzle.

This would facilitate placement for soft or silver-soldering, give more bonding surface, and better replicate original appearance.