Thank you Udo; that must be the VIANNA that came listed in Sousa Viterbo's work (dated 1908); although we can only guess that he is the one whom made this lock. If so, it must have been in his early active days, judging by the type of (flint lock). Viterbo mentions in his work that he includes A.J.P. VIANNA in an opuscule dedicated to Portuguese inventors (INVENTORES PORTUGUESES - 1902). I will try and acquire a copy, to dig into this Vianna's activities.
I am amazed with pictures you post; they were released out there by myself

. The first is a somehow rare lock posted
HERE-
The other one was posted
HERE.., a page edited and copied from ESPINGARDA PERFEYTA.
I am glad that you archive such interesting material

.