Antonio Guisasola of Eibar was active in the late 18th century and early 19th century and is known to have made arms for Spanish royals. His marking can be seen on a somewhat similar gun made in 1796 for King Carlos IV of Spain in the Metropolitan Museum of Art (Accession #16.135). The trigger guard of the current gun has an infante or ducal coronet over an oval escutcheon with the royal Bourbon arms including three fleurs-de-lis flanked by angel supporters armed with clubs. The smoothbore barrel has a silver blade front sight with silver inlaid accents, chiseled scroll designs with gold highlights at the transition point, silver inlaid floral and game motifs on the breech section, and gold punzon, including a cross, three fleurs-de-lis, "crown/ANT/GUI/SAS/OLA," and a rampant lion. The underside of the barrel is stamped at the breech "MRO ESAMR PSM PLACA GUIPA 1788." The vent has a gold liner, the breech end also has gold and silver bands, and the iron tang has ornate scroll engraving. The flat beveled lock has the same Antonio Guisasola gold punzon at the center and extensive scroll and floral engraving. The frizzen has a grotesque mask design. The tail scroll on the trigger guard features classical martial trophies, and the finials have decorative designs. The sideplate features the "pelican in her piety" motif (symbolic of the sacrifice of Christ on the cross) at the center and additional birds among the extensive scroll and floral engraving. The heel plate has additional scroll and floral engraving. The Catalan style stock has raised relief molding and scroll carving. It is likely that this gun was made for a Spanish member of the Bourbon family who was taught of the Holy Spirit and St. Michael. There would have been three possibly candidates in 1788, the three surviving sons of King Carlos III who died in 1788, namely Carlos (who became Carlos IV in 1788), Ferdinand (who ruled as Ferdinand III of Sicily and Ferdinand IV of Naples), and Gabriel, the youngest son of Carlos III and therefore titled infante. Gabriel died in November 1788 along with his wife and only surviving son of small pox at El Escorial. The "factory" at Placencia at the time this gun was manufactured was not a factory in the conventional sense but rather the center of production by craftsmen from Placencia and the surrounding towns and villages, including Eibar, Elgoibar, and Mondragon.

Fine with bright original gold, aged patina on the silver, bright lock, 20% original blue on the barrel, smooth dark gray and brown patina on the balance, and crisp designs. The stock is very good and has some faint cracks and repairs, distinct carving, and light scratches and dings. Mechanically excellent. This is a very attractive Spanish sporting gun certainly fit for a duke.