Hi Dana,
The three persons listed in the diccionario are not relative to arms making; the first had a profession hard to translate from catalan 'slang' but is rather early (1533) for the subject in question, the second was a glazier and the last was a sculptor of nativity scenes.
On the other hand, you can not discard the probability that the name in the lock plate was 'invented' to give the blunderbuss a Spanish taste. Also the barrel indeed transpires an Otoman/Tuekish look. Further, the letters on the maker's seal don't seem to match with the name in the lock.
You might as well don't pay any notice to what i am saying

.