A couple of 747 jumpseat remembrances.
Years ago I got a jumpseat on a 747 freighter. The newhire flight engineer gave me the required egress briefing. She said that if we need to use the upper deck slide 'Grab ahold of my belt loops and you'll be the second one off the aircraft!'
I jumpseated ORD-NRT on United prior to 9-11. The plane was booked full with standby's listed and there were three FO's on the B-744. It was one of those boom times pre-BK pilot contracts with a little featherbedding. The third FO was added to 'plot' the course on overwater routes. I think a first class seat was used for crew rest in those days, I'm not sure.
The captain warmly welcomed me onboard but the FO in the right seat seemed to vet me rather skeptically. He asked for my ALPA card while flipping though his copy of the Jumpseat Protection List. The captain later took me aside and apologized for this bit of drama from his coworker.
Even though the flight was oversold the purser somehow redid the pax count after the doors closed and she gave me a first class seat for the journey. In those days you could drink alcohol at United as a jumpseat rider as long as you didn't return to the cockpit for eight hours. I was treated like a minor deity and it was great.