I have a number of hollow ware pieces (mainly tea sets) of 19th century quadruple plated silver by manufacturers such as Meriden B, Wilcox, etc. When I clean/polish I keep running into the same problem: of the stubborn black stuff that remains behind, I'm not sure what is tarnish, what is lacquer and what is actual wear to the base metal. The ornamental design work can further aggravate the problem--I don't have near this much trouble with the newer electroplated stuff! Can anyway provide a rule of thumb for what's what and when it's time to stop cleaning? Thanks!