I think the 747-136 eventually did the West coast to replace the 707 and VC10 but with a YYC or YEG stop ?
Re NBO/JNB I think it stopped at FCO or FRA (certainly at first) as NBO non-stop was too far
They also went to the Middle East - Far East - and Australasia but with oodles of stops
Try and find a mid 70's BA time table and that will help you or this
https://www.routesonline.com/news/38...ental-network/
Also the LHR-LAX was op'd by ANZ DC-10 30's on a lease with BA until the RR -236 arrived when they took over the West Coast