Redfish,
My ChiCom pistol is gone as is all the documentation. I gave the gun to my brother-in-law many years ago, and I doubt that he even has it anymore.
I am also not talking about just international flights. I flew back from Vietnam on a commercial aircraft chartered by the US Military, and they would not allow carrying the weapon in my carry-on baggage. After I landed at Travis AFB, CA, got new uniforms, and had a steak dinner, I took a cab to San Francisco Airport to fly home. I was informed that no US airline allowed fire arms in their carry-on baggage. Since there were no security checks, then, the weapons in your carry on luggage was based on the honor system, and nobody asked you to declare that you had a weapon in your checked baggage....so I am sure many people carried them on board.
If you and your party of 15 were allowed to carry weapons on some airlines, it may have been permitted for the specific group you were in, or certain other groups...but i'm sure those were the rule specified by a few airlines and if the airline did not allow weapons in the cabin, the Captain had no say in the matter, if he wanted to keep his job.
If you flew on the few airlines that allowed carry-on weapons, then it may have been up to the discretion of the Captain....But the mass majority of airlines did not allow guns in the cabin, although I recall seeing some rifles on-board that were in cases and were stored in closets by the stewardesses...in the 1st Class section of the plane.
Also, remember at that time there were no security checks, and if you had a gun in your carry on bag, nobody would know if you never mentioned it. If you asked, most would tell you that you had to put the weapon in your checked baggage.
...Rich