Some of the most beautiful work of this craftsman, and many others, are in this book “Liège Gunmakers through their Work. 1800 - 1950”.
For more detail see: LIEGE GUNMAKERS
PASSENBRONDER J.A.
I find a PASSENBRONDER J.A. Liège (1858) (JAP?) who filed 2 patents:
No 005506 03/02/1858 Forced ball system
n° 005780 the 13/04/1858 Modifications to the system of forced bale and stuffing rod (brvt ppal n° 005506 of 03/02/1858)
at a time and for a type of weapon that might match ???
HPH