crewmeal:
The ANZ DC-10s were all DC-10-30s (KSSU fit). (I used to fly one of them for Air Pacific of Fiji).
I say again, with a DC-10-30 it was always possible to do LON - LAX with a full load.
The first 6 Laker DC-10s were DC-10-10s which could never manage LGW - LAX non-stop and always made a stop at BGR. This wasn't altogether a bad move since the passengers cleared customs and immigration quickly and pleasantly in BGR so, on arrival at LAX at the West Imperial terminal, they were treated as domestic passengers, picked up their bags and left the airport so avoiding the long queues in the middle of the airport.
It was occasionally possible to do a direct flight from LAX - LGW with the DC-10-10 but that could only happen if we had approximately 250 passengers or less and that didn't happen very often.