OP might want to have mods move to the gunsmithing section…
That said…. Ceracoating proved the only good option on this rifle which had a stainless barrel — so would not rust blue.
So Doug Turnbull came up with a Caracoat that beautifully matched cold rust blue. And is so thin that it has no effect on the engraving… enhances it beautifully.
This is a .470 Capstick in the style of John Rigby… on an Eddystone action. Engraved by John Adams.
Not something that would normally be considered for coating. But the results are spectacular!