A Radical Idea:

The Krag Trigger/Sear assembly is anchored to the receiver and pivots on a 'knuckle' that is on the front part of the Sear. This 'knuckle' fits into a hole machined into the receiver. The 'working' surface is the outside of this 'knuckle'.

There is a manufacturing hole through the 'knuckle' and a blind hole at the bottom of the receiver recess for the Sear.
A 'Stepped Pin' could be fashioned to serve as a support pivot for the trigger/sear assembly.

This pin might provide a smoother pivot, through internal support. Since the two holes are different diameters, the pin needs to be 'stepped'.

(If I had a Lathe and better understanding of steels, I would make one and try it out).

These are approximate dimensions; the larger diameter is for the hole in the receiver.
If such a pin was inserted, large end first, into the 'blind hole' in the receiver, the smaller diameter would point outward and serve as an 'axel' for the sear/trigger assembly.

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