Thanks, Jenny. I'm not so sure about Peak? Some have mentioned Wookey as a contender. Whatever it was meant to be I think it looks like a body of water and very fanciful to the point of fantasy!
If I were writing a guide to multiple Show Caves, with a drawing rather than a photo for the cover, I'd deliberately make the drawing a composite of several caves. Make it look more interesting and avoid appearing prioritise one cave.
Tony Oldham's prints from 1952 to 1967 have been added to MCRA. Unusually and to his credit they all have a cave name, are dated and have names of the figures present.