[Jim McDougall]

Fernando, thank you so much for staying with this intriguing topic, and especially for all the work you have done in translating, searching resources and compiling all of this valuable data. I admire your tenacity as well in the deductive reasoning in observations on the material.

This especially with the well supported new information on the markings of Julian del Rey, which in addition to the half moon, adds the curiously described 'MUNDO CON GRILLOS'. It is fascinating to see this come out to mean 'mundo' (= world or globe) and the 'grillos' perhaps tenuously also meaning 'shackles'.

While I am trying to imagine what these markings look like, I can add some interesting and potentially associated notes pending more on translation.
It is always curious where makers or tradesmen got ideas for their chosen guild or trademarks.
In the 18th century, the Spanish military arming rapiers were somehow termed 'bilbos'. I recall researching this curious term, and finding the detail on the Basque port of Bilbao in Northern Spain. Apparently the term had earlier use by Shakespeare in his "Merry Wives of Windsor" , where it is noted that swords of Biscayan (Bay of Biscay there) iron were called 'bilbos' (for the port of Bilbao).
I found also that the Toledan masters used iron from the Mondragon mines in Basque provinces, perhaps lending further to the Bilbo term.

Now here's the pitch, the word 'bilbo' also refers to a long iron bar with sliding shackles and lock worn on ankles of prisoners.

Not sure if this is 'cricket', but here is a word for sword and famed iron (termed alma de hierro, =soul of iron) linked to 'shackles'.

Tenuous yes, but intriguing just the same. Now if we could just find what this mark looked like!