Martininut,

I'm not much of a Martini expert, but I have some data for you.  The firm of Hermann Weirauch started in 1899, if my source is right, and started out making firearms, but their chief claim to fame is the precision air arms they made.  It looks as if they made .22 target/sporting rifles on Francotte Martini actions sometime in the pre WWII era.

You might not want to pitch that rear sight too quickly.   Subject to correction by the more knowledgable people here, I recall that there were some shooting matches in Germany that did not allow either telescope or diopter sights, only open ones.  Naturally, the keen competitor would want to slide the rear notch back and forth to achieve the best focus possible for his eyesight.