One of the Princess's supporters says of the revolutionaries "I spit on them." Chuff comments "That's a terrible thing to do. Penalty 40 shillings". This reference is to the standard British Rail penalties for fare-dodging and for spitting (hawking) on trains.
Chuff's comment, when leaving the revolutionaries' base with his cat, "Come, puss, only nine more miles to London...", is likely a reference to the story of Dick Whittington and his cat. Whittington's story is told in the poem, "Dick Whittington and His Cat" by Clara Doty Bates.