The finish on this gun is definitely nickel.
Engraved or nickeled first? Given the depth of the engraving, it seems like the nickel would break through, but I don't see how the detail would still show if someone nickeled over it.
On another note, I really hope you have a Photobucket Plan B for when you go on to your reward (a long time from now). You have some of the most spectacular threads on the forum and if they become just more "photobucket internet potholes", it's going to be a sad, sad day.