As you demonstrate so well, contemporary accounts, records, advertisements, case labels, and publications are the best sources for unravelling the story of gun development in the 1850s and 1860s. But I have to say, what really made my week, Gene, was the reference to the Blanch scrapbook items, and the 1855 bill of sale for a Beringer gun. It suggests with real evidence that London makers sought foreign guns to study and copy. Research on the competition makes sense! It also helps explain how and when foreign innovations started turning up in British guns, and the reverse is probably true as well. While the French made great advances with percussion ignition, it looks like much was based on getting their hands on a Forsyth ‘scent-bottle’ gun. The quintessential British lever-over-guard might have been inspired by Blanch getting his hands on that 1855 Beringer... or by another maker with another gun. In any case, it shows how there might have been a cross-pollination of ideas. The fairs and exhibitions would have been another source of professional curiosity, and comparison.