not easy to find anything about the Nickel AG and I must go over Hertel&Reuss:
Hertel & Reuss was a manufacturer of optical instruments, based in Kassel, becoming part of the Gerhardt companies after a bankruptcy in 1995. H & R was founded in 1927 by Otto Hertel and Edward Reuss. In the 1970s H&R had around 400 people and exported worldwide.

Today, Hertel and Reuss is a brand name and distributed by the Nickel AG in Naumburg, northern Hessen. Before the takeover from the Gerhardt companies the rifle scope and binoculars maker Nickel AG was based in Marburg an der Lahn

I did not know they are allways making the 6x42
http://www.nickel-ag.com/en/products/scopes/s642.aspx

here a 6x42 C so I suspect its the third generation. its a scope they dont sell every day in germany today.

EAW is the right adresss for MS claw mount parts.