This was face-to-face with customs at point of delivery by a person who had done his and their homework, with their official documents as evidence. Generally no one wants to look stupid. They gave him the gun. A pleasant nature and quiet assurance helps. It works for me with customs.
I tried the same approach several years ago when I attempted to legally ship a shotgun via the Naperville, IL post office. The morons still refused to ship it. I finally went over to the neighboring community of Lisle IL and shipped it from their post office. It's stuff like that that makes me glad I no longer live in Illinois (among many other things to numerous to list). It's a shame too because I miss my many friends who still live in that state.
Steve