Roy, value is relative. Geography has as much to do with sale price as any other factor. Around here (Western New York State), I'm sure you could get $1000+ at any Rochester Gun Show. That's without the accessories, but except to a collector, they're not considered valuable (again, around here).
The plating...Well, to decide whether it is chrome or nickel, hold it next to something you know is chrome - an automobile bumper or a motorcycle fender is good. If it is nickel, it will look 'yellowish' compared to the chrome 'blue'...
Plated Lugers have their own followers...Some think they just look neat. Especially with aftermarket grips of Ivory...
There is even a hierarchy of sorts, with nickel reigning...
Unfortunately, plated Lugers usually have the snot buffed out of them to make them shiny. Original issue Lugers have tool marks and sharp edges. Buffing them out is just a crime...
Collectors won't have much interest in your Luger, but the Average Joe will eat it up!
Edit: Just read David's comments on stripping & re-blueing. None of that will restore the edges or the tool marks or sharpen the markings. Exactly the opposite.
If you really want to invest some time & $$$, consider having a professional restore it. Ted Green ["Thor"] here on this site does an excellent job at restoring abused Lugers.
If it is an inheritance, then consider leaving it as is (if it has any value to you personally). It is what it is. Someone thought it looked better plated. If that someone was special to you, then maybe it is better off as it is...