It's the only AUK event I know of at the moment that's suitable. I guess I need to wait to see if others pop up. For example, where is the National 400 going to be in 2017?
I've also been working on/daydreaming of a nice London - Sussex/Kent coast - London loop route.
Incidentally Severn Across seems to have been rebranded as
London Wales London Unless I've got things muddled up. I think they are stretching credibility just a bit by calling Gerrards Cross "London". It's not London by any definition that I can think of.