Webley pistol windage adjustments

[Abasmajor]

My Webley mk 1 does not shoot where I aim, and the sight is only adjustable for elevation.

What is the accepted method of windage adjustment on these pistols? Barrel bending?

Hello,
Certainly not barrel bending. A limited amount of windage adjustment is possible by enlarging or elongating the rear sight blade retaining screw slot with a small round needle file sufficiently to provide some lateral movement in the direction required. Reproduction blades are readily available should you not want to modify an original item. Remember to move the rear sight blade in the direction you want the group to go.
Regards
Brian

PS Ignore the daft comments from those such as I.J. below who will never appreciate these fine examples of British engineering.