Have to give greg the points for the whiskies! His answer is a re-wording of the 'official' answer. (There goes No.8) Declan: the spacing for the cipher is deliberate. 'okthen' points the way to some extent. Bassic: The rolls royces, you're on the right lines. The 'baby farmer' is "Buttercup" (greg) and Sir Percy Blakeney was 'The Scarlet Pimpernel' greg has given the reasoning behind 10c, 10 a & b should not be far behind.
And, to answer Declan, I didn't solve the cipher in Q18. But I have a copy of the official answers!