That is an absolutely awesome bit of acting on Richardson's part and I can quite see why you had sudden Wimsey flashbacks. Although further to your *** footnote, I suspect that you would need not just length to achieve psychological plausibility, but the sort of retconning that turns the Fat Patrician of the first Discworld book into the carnivorous flamingo of Guards! Guards! ("It's the same character, but written by a stupider author") - perhaps a series of books about Lady Mary Wimsey, the famous detective, including one in which she rescues her rather stupider little brother Peter from the clutches of a gold-digging romance author with Soviet sympathies who turns out to have poisoned her previous lover? Of course the spying would have to teach Peter to grow up (the male equivalent of marrying Charles Parker and spending your life doing housework on a limited income), so we could feel the proper appalled sympathy-mixed-with-contempt that Richardson is so good at inspiring.

I don't see why LPW wouldn't have been at Bletchley, though. It wasn't all maths - one of the methods of recruiting was to put a crossword in the Times and interview everyone who claimed to have done it in under 12 minutes - and he's clearly been rubbing shoulders with cryptologists before the war. But I agree that he wouldn't have stuck it for long.