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.