Times have sure changed!
Only time I ever flew with a firearm was many years ago, Winnipeg to Vancouver. I had a Luger and 128 rounds and a French St. Etienne "Le Municipal: with 12 rounds in my carry-on. Also had an RCMP Permit to Transport, needless to say. I offered my bag to the stew so she could put it in the crew cabin, but she said 'no problem; you can carry it' and that was the end of that. The fact that I worked for the airline at the time might have reassured her a bit, but, I don't think THAT much.
And I didn't even have the old 8 fly us to Cuba!
If I were doing it again, antique or no, I would have every permit in the WORLD handy and it would be in my checked lugggage, in pieces and with one critical part in my pocket.
tiriaq, of course, is right.