L42A1

[Surpmil]

IIRC they are soldered on, and presumably pinned. If no cross-pin is present, then it should be easy.

Peter's method of aligning the front and back sights IIRC, was to remove the backsight, but re-insert the axis pin. Remove the front guard and blade, invert the barrelled action on a sufficiently flat surface (your wife's granite counter top?), rest the axis pin on a gauge block (not on the "ears" the pin passes through) and rotate the front sight base until aligned.

The only issue I can see is that the flat on top of the front sight base is so narrow that a good deal of care and back-lighting would be needed to see that it was actually aligned; any burrs or other damage to that face would also interfere. A steel block or bar an inch long or so, with the male dovetail of the sight blade machined into one side and inserted in place of the sight blade, would make the process quicker and more reliable I suspect. (both sides machined perfectly parallel obviously)