These are the documents and sites that I use in my research. I hope they can help you as well. This page is a work in progress — please excuse changes as it grows and its organization evolves!
Catalogs and price lists
Online research resources
Business legal records
Crowns stamped onto copper are excellent clues to previous owners because the design of the crown is highly specific to the owner’s rank and country of origin. The Wikipedia page on Crowns (heraldry) gathers drawings of crowns from multiple current and historical regimes and is the place I look to investigate the provenance of crown-stamped pieces.
Books about historical coppersmithing
Online books available for free
Art of Coppersmithing, by John Fulles Sr., 1911. He writes about becoming an apprentice smith in England and learning how to craft a series of increasingly more complicated pieces, with lots of detail (even mathematical formulas) on how pans with complex geometry were cut and assembled.
Please let me know if any of these files don’t load properly so I can fix them. This type of page doesn’t have a comments section, so please email me at VFC at vintagefrenchcopper dot com. Thank you!