Greetings, DKC!
I also have a Bannerman's / Sears / M'Ward Springfield; mine is an 1866 Allin .50-70, cut to 24", and was provided with a rather blocky barley-corn front sight that was dovetailed onto the barrel. It looks very period appropriate.
I would also consider having a stud brazed to the barrel, preferably one that was dovetailed at the top to admit a small, drift-adjustable blade, to eliminate the need of hold-off.
Good Luck! Photos!
M.T.Marfield