Hello all I have a problem and being out of airgunning for a few years has left me short of a solution for my webley tomahawk.

I intend to shoot my Tommy in the clubs open sight competition and I have the foresight sorted out but it’s the rear sight that is the issue.
Drilling and tapping the breech block is not happening on a pristine Tommy and the scope rails don’t go all the way to the end of the cylinder so a hw77 rear sight won’t go on and the rules are diopters are not allowed.

Any ideas gratefully received!

Regards
Me