Mark, I'm glad you've kept this thread going, and probably one of the best results is in emphasizing the difficulties in identification of swords which are actually Mexican, and really not technically Spanish Colonial. When dealing with weapons which are fabricated in later periods than the weapons they in essence replicate, often even using actual earlier components, it becomes extremely difficult to accurately assess them.
The 'round tang hilt' as I have mentioned, was essentially a hanger type sabre which evolved around the 1820's, and sought to add a multiple bar handguard as seen on European military sabre hilts. In "Spanish Military Weapons in Colonial America 1700-1821", I believe the term used loosely was 'gavilan' to describe these hilts (the term if I recall refers to 'sprouts' as in wheat etc). As may be expected in the frontier environment in which these were fabricated, there were countless variations, and as mentioned, often using blades from surplus, trade or damaged weapons.
It would be difficult to establish definite periods of use, as popular use of these was essentially to carry forth traditional fashion from contemporary military styles and in some cases attempts to preserve the heritage of the Spanish ancestry, more from that point of view. It was a struggling young country seeking to create its autonomy and its own identity, which clearly reflected the diversity of its people.
The espada ancha itself developed primarily out of the recognition of the fashions of earlier times and the gentry of European countries, with one of the most likely influences being English hangers of the 17th century. While it evolved into essentially a utilitarian weapon of the frontier, very much like a machete, awareness of more military style weapons, and the multiple bar guard became popular, and probably carried well into the latter 19th century.
Even during the Porfiria, the long rule of Porfirio Diaz, swords were an element of the loosely styled police units known as 'Rurales', who wore many variations of sabres from vintage sabres of earlier times, to refurbished versions as described.
The scroll type quillon terminal noted is well established among examples of the espada ancha, and other sword variations in Mexico, which of course were produced throughout the 19th century.
The sword with the heavy blade and the unusual eaglehead hilt seems very much like the 'court' type dress swords (in this case with heavy fighting blade) which were often produced for officers or officials in what I would like to call 'regency type' weapons of Mexico. It seems that during post colonial (after 1821) times the attempts to create an 'Empire' beginning with Iturbide, also brought impressions of elevated stature to often relatively minor figures in outlying provinces and cities who sought to emulate regalia of the court atmospheres of Europe. The call for 'dress' fashion weapons was often answered by local blacksmiths who created traditional swords accordingly, and with in my opinion, admirable skill using materials available.
These are unfortunately often regarded dismissively by collectors, and clearly often misidentified, but in my opinion they represent the tenacious spririt of this diverse people seeking national identity in the most turbulent of times.
The final words in Bill Adams article, "The Unique Swords of Old Mexico" (1984) notes concerning these weapons that "...there is not yet much scholarship on the subject. I can see in the swords themselves much about the people who used them. For now, that is enough".
Well said about the weapons, but for me...it is never enough
and like most of my work on studying weapons, it remains 'work in progress'.
All best regards,
Jim