I've had the joy of flying on 4 US carriers operating 741s, and SPs. Click for large version
Photo © Dean Straw
American had a 747 ready to take over Braniff's DFW-London route as soon as Braniff filed chapter 11. In additon to Braniff's Orange SP and it's American replacement, I flew on several Pan Am 741s, including Ocean Rover, and on a NW domestic leg (DFW-SFO) of a Tokyo run. Alas, I haven't flown on a 747 since that 1986 flight, and certainly I have not had the chance of flying the 744. I guess for domestic traffic, all US airlines would rather have frequency than volume. Japan seems to be able to support domestic 747 routes.