Re: Nickel vs chrome plated sperzels?
Nickel has a "whiter/richer" sheen like silver, and is more relaxed and cloudy in its shine overall. It is more vintage-y! It starts to age as soon as it is used, but nickel feels so friendly to the fingertips
Chrome is generally more shiny, and "bluer", and retains a mirror-like finish. It says brighter longer. It has more of a mirror finish in the real world, and and is considered more garish or kick@ss, depending on one's perspective. Chrome is great for low maintenance.
Polishing nickel with a common household metal polish will work, but I do not know what brands are available to you. Keeping the guitar in the case when not played will extend the life of the strings as well as the shine of the nickel hardware. Nickel plating is softer than chrome.
I have a Gibson with nickel tuners, and chrome bridge and tailpiece. The nickel/chrome contrast between this 25+ year old instrument doesn't bother me a bit...but a set of covered humbuckers might determine what looks "right" for a particular guitar.