Many thanks to furhmann for the images and all the effort on the translation of the Anton Vinzenz Lebeda info docs.
Yes, another grainy image but it will have to suffice for now.

"The muzzleloader with percussion lock constitutes the main body of his work, and his successful 1828 invention of the so-called Prague boxlock was often copied in the continent and in England. At the Bohemian Country Trade Fair in Prague (1829) Lebeda received a silver medal, and on 22.12.1830 he received a further privilege for a “hunting gun with a safety catch”."
"Cap lock for percussion guns, patent 1828; Hunting gun with a safety catch, patent 1835." - Ref. for translated 1965 Austrian document.
Translated from the doc and I wonder if this is December 22nd 1830 safety catch? Also what might be the "Prague boxlock"?
Kind Regards,
Raimey
rse