the bright part of the emblem is the protective lacquer finish that has not worn off yet.
the darker dull area is where the lacquer has worn off exposing the underneath metal.
to refurbish this particular emblem – you would have to remove all the finish with a chemical
such as acetone or lacquer thinner. Very carefully wet sand the entire emblem with 400 grit Wet-or-Dry paper.
here is the rub: if your emblem is 100% brass, you would proceed with the same manner of refurbishing
the knobs and lettering described in another thread. Lightly spray paint with black then sand off the top area
and the end result would be a polished brass emblem with black lettering.
if your emblem is only "brass plated" steel or other metal, you would be looking at a costly trip to
a metal refinisher to have it professionally restored.
scratch the back of the emblem to see what the metal actually is. Also, put a magnet to it – it will not stick to brass.
then – with 300-400 grit paper, sand the back of the emblem – come back for further analysis.
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