@Hugo990 , Thanks for the further suggestions.
1) Each of the London listings do state in the SUB-title "Room in London" and at the moment there's not room in the title itself to fit that in. However it's something worth considering.
2)I have stressed London location and also transport to the centre in the descriptions. When you mention relevant searches, that would still not solve the problem of guests (the majority) who if coming to London simply do a London search. Guests who are looking for a place in this area and do a search of this area can see my listings.
3)Same applies to your 3rd point.
Latest I have heard from the escalation team (yes, at least it's got that far) after I once again raised the issue with Airbnb was that they were currently investigating the issue and would get back to me with a resolution. Well, going by past experience, I'm not holding my breath!