You can remove the nickel yourself. There are chemicals you can buy that will take it off in a few hours. I am not a nickel expert but it looks like you will have significant pitting on that barrel under the nickel.
I would leave that gun as is or remove the nickel and have a bead blast and blue or bead blast and chrome or nickel. The bead blasting will probably hide the pitting.
That is going to be a cool shoooter, no matter what you do with it.