If i dare point out a couple discrepancies on your notes.
The sword model...
As you kow, the term Bilbo (Basque/Euskera for Bilbao) is somehow a catch-all word, created by english speakers to refer to swords imported from that capital city of the Biscay Gulf province, region of the famous Mondragon steel. In strict terms, to call a sword style a Bilbo falls into some contingency. In the case of your example, if i well discern, it would be a mounting sword (Espada de montar), for which the Spaniards had a name that resembled is assymmetrical guard shells, called Boca de Caballo (horse mouth). Once it has the Carlos IV (which i don't view as being a remark), this both means it is a military issue made to Royal property (the civilian version also existed) and, Carlos IV having reigned between 1788-1808, your sword would be the "new model", as the first one was issued durig the previous Carlos III realm.
The second blade iscription ...
Although i didn't figure out its actual meaning, it looks consistent with some letters of the initials referring the military corps it was produced for, as usually done.
The mark in the ricasso ...
This is somehow intriguing. Starting by the attribution given to Maria Hortuna (better spelt Hortuņ
a). Maria is a woman's name and we don't know any records of a female sword smith; unless the author eventually picked the sword smith's wife at reading whatever notes.
On the other hand, all three Hortuņos registered in Palomares chart (and not only) were of a Basque family (Ortuņo) that worked in Toledo in dates prior to this type of sword, from grandfather 1604-1613 to grandson registered in 1637.
Furthermore the letter H
's they used as mark, together with the Toledo symbol, are not consistent with the one in your blade ... assuming yours is a H
See Palomares nomina for the three Hortuņos and their marks, positions #22, #38 and #80.
... And forgive me if my assessments would do no more than misguide you; iam not even a Spaniard.