Somewhere in Limsa Lominsa, Vylbrand, or Ul'dah. All of those places/nations have had good trade relations with Thavnair for centuries. Could've easily gotten shipped in with a crate of goods, or Lominsan pirates sacked the ship and took the weapon and then the pirate dies or whatever and its abandoned somewhere, or the merchant ship sinks and it washes up on the coast somewhere. Lots of possibilities. Perhaps there's a roleplayer whose character deals in foreign antiquities? Or maybe it was just on sale at a booth in Hawker's Alley and your character didn't realize it was special until later?
