Has anyone attempted to do the PVD process to door hardware and taps after they have the finished product?

The reason I ask is, I really like the black chrome and gold but all the gold appears to tarnish rapidly. From what I can gather, PVD won't tarnish but none of the hardware I like comes in PVD. I've found a Melbourne crowd who'll do PVD, but as it's an embedding process, I've no idea whether it can be done to say, a chromed tap or if it has to be the raw material.

Any clues?

PS....does anyone have the PVD (gold colour) and is it as good as they say?