I got a Dietzgen slide rule still in a very good shape, only there's a presence of a green patina on the surface of the cursor, I think due to the contact between the metal and the leather of the case.
Which kind of metal is the frame cursor made and how may I clean without damage it?
How may I remove dirt and maybe a few little scrapes from the glass surface (his is not plexiglass isn't it?)
Thank-you in advance for your hel and advices.
Edit:
I've done just now, using a piece of cotton and a NUNCAS'soft polish for metals the one my wife uses for cleaning at home, the window of the cursor (it's really glass) with water and soap and ...there's no a scratch (!)
It looks like just came out from the factory, 63 years ago, it needs only a magnifier like the ones showed by Kimberly, to help in reading.
Edited: 18 Sept 2013, 1:36 p.m.