Ai Michl, don't shoot me
.
I was only willing to show that atypical (?) patchbox; the lock happened to be in the same page and i decided not to delete it.
But let me tell you that the book author was aware of the Prussian influence in the lock depicted. In the text, and in line with what Chris reminds, he quotes the several gunsmiths that were among the large number of German imigrants that in 1710 fled to the New World for religious reasons and settled on the territory of Pennsylvania, continuing with the production of their favourite rifled flintlocks which, after known evolutions, originated the Kentucky rifle.
In a different perspective, the author assumes the virtual Prussian origin of the posted lock, in a page where he confronts de various lock typologies, as here (partly) attached.
By the way, the book is called "Great Century of GUNS" (ref. XIX century), with texts by Branko Bogdanovic and air-brush illustrations by Ivan Valencak (ISBN 0-8317-4070-1).
.