Interesting thread(s).  I have professionally restored Pre-WW1 cars for
many years (not doing it now, though).  Plating has evolved over the
years and, yes, most of today's nickel used for plating is not the same
as nickel used during the years we usually deal with.

In the Prewar years, plating was usually done by plating with copper,
polished, then plated with nickel, which came out of the tank as a dull
finish.  This was then left as-is, or polished with 180 grit compound,
giving the finish a "brushed" look, called "Butler plating", very
similar to today's "pewter" finish popular on bathroom fixtures.
A third option was to polish the nickel to a smooth, bright finish.
This finish is subject to oxidation, becoming a dull finish over time.

To prevent this deterioration, late in the 1920s, a thin layer of
chrome was put over the polished nickel.  Chrome has a bluish tint to
it, so the chrome finish didn't match the old polished nickel finish.
Today's platers use a different nickel, and aerate the tank, so the
nickel comes out bright, ready for the chrome layer without buffing.

It is worth looking for a plater who understands the difference in the
nickel finishes and will provide you the correct one -- the parts look
completely different.  I have "debuffed" chrome parts with the 180 grit
polishing compound and ended up with a very close "Butler Finish" on
the chromed repro parts.

David Dewey

 [ Found at http://www.chicagosilver.com/story_of_sterling2.htm :
 [
 [   Butler Finish -- The care of silverware was one of the duties
 [ assigned to the English Butler.  In the course of years of hand
 [ rubbing, the silverware took on a distinct lustre which to-day in
 [ modern Sterling ware is simulated by a process of manufacture known
 [ as "Butler Finish."  This finish is sometimes called Grey Finish or
 [ French Grey Finish.  Each may show a varying shade of soft finish,
 [ but both fall under the general category of butler finish as here
 [ described.  The finish on Sterling ware is produced by buffing, or
 [ polishing the article with different kinds of abrasives.  The
 [ various terms applied to soft finish are more particularly a trade
 [ convenience to indicate the abrasive used rather than to describe
 [ standard shades or tones.
 [
 [ -- Robbie