any rust has already shown the protective zinc has been eaten through and you can make it look nice, but it will eventually come back, nature guarantees it.

any major parts you can get replated, although there will still be the pitting from corrosion showing.

getting the chestnut media out of Philips head screws sucks. Just buy new ones, sooooo cheap and their new.

first job on a playfield, IMO, is to fix down both the general and switched illimitation braid. Hardware in the way will make it near impossible.