Good stuff! These unmarked Potzdam style locks/guns show up in America (one similar lockplate was recovered at Point of Fork Arsenal in Va). It is tempting to link them with this:
Moller V1
MUSKETS CONTAINING GERMANIC COMPONENTS 045.9
Paul Wentworth, a British agent in Amsterdam, wrote William Eden in
London on October 21, 1777
reporting arms which had been acquired by a German, Johannes Philip Mercklé,
in Liège and transported to Amsterdam. Included in this list were “3,000 fusils of the Prussion Model,” “2,000 lighter fusils,” and “5,000 Spare Gun Locks.” He also stated that Mercklé and Silas
Deane's brother, Simon Deane, were to sail with these arms to America in a
new ship, believed to have been named Christine. This ship, carrying 4,000
gun locks and other arms, sailed on January 26, 1778, bound for Nantes,
France.
for comparison the normal Potzdam markings