Crusader is correct, as this is a Victorian era ladies fashion item, a decorative buckle worn on a cloth belt. This style dates to around 1870-1880, +/- possibly a few years.
Thank YOU AnnieF, for your kind compliments, regarding our group here!
My thoughts are the "L" is merely a trick on the eyes, and what we are seeing is actually a few bumps or flaws from manufacturing and/or changes in patina color.