I think you could bring it a long way back by hitting the surface with some wd40 and light sanding to remove the surface rust. You could also go over it with a soft wire brush or drill attachment if there is rust inside the etching. I’m not sure how much more rehab it might need after that, other than a resharpening to restore the edge.
I’d be careful with chemical treatments unless you know how the finish will react. I have very little experience with them, so perhaps someone more knowledgeable will have better advice there.
Good luck!
The Girl With All the Gifts was pretty good, based on the book of the same name.
For comedy, one of my faves is Stranger Than Fiction.