Well, you just try taking a decent photo of wriggly squirming pusscats!
Thank you everyone for your fabulous suggestions for names. It's been an interesting task giving a pair of almost identical kittens monikers that will do well for adult cats. The only difference I can tell at the moment is that one has blue eyes and the other green; but most moggies' blue eyes change as they get a little older, so I'm just going to have to learn to distinguish other features and personality traits.
Claude and Eustace it is then, the twin cousins of Bertie Wooster who turned up far too early in the mornings, perched on Bertie's bed and nicked his breakfast. Trouble was their magnet. Sounds about right. Blue eyes is Claude, green eyes is Eustace (front).