anyone know who made

[fausto]

Hello!
I have surely seen in past some pictures on eBay of a William Tell marked front sight adjuster. It was - if I remember well - for 7,65 Parabellum Swiss Lugers. I collect Swiss Parabellums and related items and I have a wide range of sight adjusters. They are "all" commercial, made and sold to Swiss shooters along the first half of 1900. No one, as far as I know, has been found in military supply.
There are many models and some are really beautiful, complicated and well made, while others are less accurate and attractive. Some, with rotating "pusher", will damage the blue on your sight base, other, with just "pushing" pusher will not damage that. Some are marked (sometimes with colorful names as... William Tell or with the maker's logo) some are not.
Take care: many, marked with Swiss cross (both for 7.65mm and 9mm Parbellum) are more or less accurate recent reproductions that you will find at near all gunshows.
Hope that this can help...
Fausto