Fernando, thank you so much for the notation, and it is true, the cuphilts are very much a knee weakening affinity for me, but at the moment I really could not add much to the great discourse you and Manolo had going. The question of terminology and semantics clearly come to the fore as described here, and prompted me to return to notes to reconfirm my perspective.
When returning to the thread it was delightful to see that Marc had written a superb treatment on this dilemma of the term 'bilbo', and its application in traditional Spanish swords. In the eloquence that is his hallmark, I think this is a perfect explanation of the developed use of this term as well as well placed observations on the classic Spanish and Portuguese cuphilt swords (I know you hate the collective term Iberian Fernando !
It seems to me that in the 17th century and of course through the 18th, there was prolific import of German trade blades to these markets, which as you pointed out, may well account for the spelling variation in the inscription.
In Shakespeare's time it does appear that 'bilbo' had become a somewhat universally applied term for rapier or sword, as seen in "The Merry Wives of Windsor" (1602, III, v.) , "...to be compassed like a good bilbo, in the circumference of a peck, hit to a point, heel to head". These terms of course seem to allude to the very geometric fencing theorems that were known in Spanish as "Destreza" which would suggest a rapier, but case in point is the use of the term.
Other references suggest the term pertaining to a sword from Bilbao, which is as noted the capital of the Biscay province in Basque Country. In Shakespeare again (Othello, v, 2) mention is made of swords of 'ice brook temper' where the Spaniards used the brook Salo near Bilbilis in Celtiberia to harden the steel, and produce swords of the highest quality.
Whether this Bilibilis might have anything to do with the possibly related term 'bilbo' remains a question, but corrupted words in transliteration or colloquial parlance can sometimes lead to situations such as the term 'bilobate' becoming shortened to bilbo.
It should be noted here that the term 'fox' is also a term used in Shakespeares works to describe an esteemed sword blade, in this case referring to the 'running wolf' of Germany or perhaps even the 'perillo' (little dog) of Toledo.
While these terms joined the ethereal 'scimitar' term in describing swords in literature, it seems that the popularization of antique weapons collecting in the 19th century borrowed some of these terms in descriptions. In the case of the bilbo term, it seems to have become associated with the bilobate military type swords noted, while the cuphilt was distinctly described as just that.
Returning to the cuphilts, these examples shown are indeed beautiful examples of the tradition of the cuphilt rapier maintained proudly in these arming type swords. If I understand correctly, most of the colonially mounted examples (often termed Caribbean) do not have the rompepuntas, nor the guardopolvo within the cupguard.
All very best regards,
Jim