Ahhh Gentlemen sorry for being a little late the P-H sight is a Model 11 and was made in several forms to fit onto the firing pin nut. The 11M was for Mauser the 11MS for the Mannlicher Schoenauer My 1962 catalogue does not mention the Enfields as they advised using the reciever mounted Model 16F fore those.

Now I have been considering "butchering a damaged P-H 16 to fit the missing slot on my Mannlicher Model 1903 but that's as far as it got.

Now the nice little tang mounted sight is a Model 10 and they all known as the Sportarget sights.

Hope that helps.