Many years back I was in charge of inspecting chrome plated seat
belt parts at MiLat Machine and Tool Company in Plainview, New York.
I even got to go to the platers to see their operation (Nelkin Platers,
New York.)  I asked questions and found out that the chrome is plated
on top of a nickel plating.

What you see in a chrome plated part is actually the nickel.  The
chrome plating is there only to protect the nickel from oxidation.
The chrome plating is so thin that it is transparent.  So, according
to my source, a chrome plated part does not look any different than
a nickel plated part except that it is protected.  An old nickel plated
part darkens a bit in time while a chrome plated part does not. That is
what I have been told and would be interested to see if a controversy
develops out of this statement from those who have experience in this.

Andy LaTorre