Unfortunately, I don't think Jack O'Connor knew that there was more than one Arizaga making shotguns because he didn't seem to mention any more than "Arizaga" in his writings. His 28 gauge is serial number 34525. His 20 gauge is serial number 49,401. Maybe we can figure out which Arizaga made Jack's guns by the serial number range. The gun that I have seen that most resembles the 28 gauge described by Jack is a Eusibio Arizaga, not sure of the spelling. It is a cased two barrel set with beavertail forend and I don't know where it is today. It was a pretty rough gun, but, then, we don't know whether O'Connor's gun may have been a bit rough too. Both of his Arizagas are still around, but I don't know if the owners read this forum.