Thanks for the welcome ubassman! Sorry, probably should've been clearer - its the same tutor via Skype and the lessons in London - we mostly do Skype lessons, as I'm not in London very much, but it's been helpful to have a couple of in person lessons when I can.
I found a tutor through this site: http://www.thetutorpages.com/tutors/classical-double-bass-teachers/classical-double-bass-lessons/230
It lists ones who are able to do Skype lessons and gives a bit of info about each person. I picked the one who mentioned the most orchestral stuff (Vera Pereira) as that's mostly what I play. I emailed a couple of folk and Vera seemed the most helpful, then we did a trial lesson for free. I'd say its worked out pretty well, although I do feel sorry for her when she's listening through headphones - must be ghastly having all my dodgy intonation being beamed straight into your head!!