BOAC must have abandoned the North Pacific route, then operated by 707-436 around 1970. It was certainly operated in 67/68 and had an optional Wake Island tech call westbound followed by a nightstop in Tokyo before proceeding as the next days' Tokyo-Hong Kong-Various x 3 or 4- London.
The VC10 from Tokyo to Jo'burg started in 1972. Originally once a week it routed Tokyo/Hong Kong/ Columbo/Seychelles/Jo'burg and then back to Tokyo with a second service operating the same route but from Seychelles to Nairobi and on to London. This was later abandoned and both went to Jo'burg and in due course became 747 operated. During the cabin crew strike later in the 70s this route kept going as the strike was only ex London and BA simply re-rostered all on the route at the time to keep doing it and never touch London.
Had BA not sold Hong Kong Airways to Cathay ,originally in exchange for a shareholding in the latter, they could have continued to this day operating all Hong Kong Airways routes,- ie all points north of Hong Kong and North Pacific. At the time it had problems making these pay even with Viscounts and thought they were of no long term interest.