Oh, these would be fun to look for. Lots of antique ephemera / book and map shops in this area, in fact doing a job soon for an elderly couple who own a shop that may have items like this.
I checked one shop in the village near me. He had some plates (I think that is what they call them) but no cephs. Saw a few interesting ones of dive bell design and dredges, both from 19th century.
We are a participant in the Amazon Services LLC Associates Program, an affiliate program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.