Kate, I've done some consulting with pizzerias South of London, and, from my extensive research, I've come to a pretty good understanding of British pizza. No offense, but a lot of it's not that good and very few establishments understand what authentic Neapolitan pizza really is. Franco Manca (Brixton) is a prominent exception, but, beyond that, I wouldn't turn to too many London area pizzerias as examples to follow. Franco Manca doesn't deliver. They do take away, which, imo, doesn't do justice to the pizza, but, I guess they have to cater to their local demographic, and, in England, take away is a huge market.
My guess is that a lot of these 'traditional' places that deliver aren't really putting out Neapolitan pizzas. In other words, they're probably only running their wood fired ovens at NY temps. It's one thing for a home baker to make Neapolitan pizzas when their oven is at it's peak and then shift to NY doughs as the temp drops, but, when a commercial pizzeria with a wood fired oven only uses it at lower temps, that's a little tacky. It's a like owning a Ferrari, but never exceeding 55 mph.