Many thanks for the responses and helpful suggestions on this topic

The San Jose option for the outbound looks promising for the dates we are looking at, and for the inbound LAX - ATL - LHR may well be possible, using Avios in WTP.

I couldn't see a way to book this combination online, does it need a phone call to BA to book this kind of trip?

I'm still tempted by Club World for the return, but as we don't have enough Avios, is there any way to upgrade for a sensible amount of cash, or would we need to look at a non-Avios solution, maybe the ex-DUB as suggested above?

Apologies if this reply posts twice, PC response was temperamental earlier, mods please feel free to delete one post if duplicated