Steve, some of the late Dickson pin-fires may have been made for the eccentric collector Charles Gordon. If you have the serial number of the one illustrated I could check that in Donald Dallas's book on Gordon. He was having muzzle loaders and all sorts made long after they were obsolete.

Reference to the Harpur-Crewe family at Calke I can vouch for the large collection of taxidermy. Calke is not far from me and open to the public; or will be again soon when Current conditions allow. Lagopus…..