http://www.foxcollectors.com/ah_fox/content/sterlingworth_4.htmlOn the forend irons, some were blued and some were case colored , trigger guards were all blued. Triggers themselves were always in the white,
never blued.
After about 1910-11 only Cyanide Case Colors were used,
not bone and charcoal CCH like you see on some "didn't know any better" Sterly & Fox restorations.1929 Philadelphia made Fox Sterlingworth non-ejector with factory cyanide colors and blueing...
Fred Heinzleman & Sons did all the original cyanide colors on Fox guns up through the end of production. Stan tried to contact them a while back, with no luck..?.. I do know up until a few years ago they were still cyanide case coloring guns. Their cyanide colors are NOT of the "tiger stripe" variety and are very nice BTW.
http://www.macraesbluebook.com/search/company.cfm?company=315736