regarding the action colour, imho this is a 'nitride hardened' action which should be silver/grey in colour.
Sometimes the lower area of engraving is blackened.
Again imho it is darkened with crud and something similar to oxidation - years of neglect?
I can't get pics up here any more, otherwise I would show my Otto Bock pre-war gun with a nitride action.

As always - I could be wrong!

Perhaps Raimey can oblige with a pic of some such 'grey' action


edit: Xausa's pic a bit further up shows such an action

Last edited by Gunter; 02/10/19 09:49 AM.