In response to Mark Van Essen's second_ request for help in restoring
brass metal plates with black background, I can only say that I have
attempted to restore some of these in the past.

If you will notice (some, not all) of the brass letters are slightly
raised from the black background.  I have had success making these look
better by first cleaning them thoroughly from any oil or grease, and
spraying the entire plate with a semi-gloss high temperature black paint
for out-door barbecues!  When dry, using a VERY flat surface, the raised
brass letters may be burnished back to brass, while the black background
remains.  This is done by carefully rubbing the inverted plate on a hard
flat surface covered with crocus cloth.

When this is done, bake the metal plate in a 200-degree (F.) oven for
about an hour to cure the paint even further.  Cool, and spray with a
clear lacquer.

This method helps sometimes, ... but if the _lettering_ was painted on in
the first place, the only remedy I can suggest, is to carefully  paint
around the lettering with India ink, using a small brush.

Are there any other readers out there who can offer any suggestions?

Bruce Clark