At the 1933 Olympia (London) Cycle Show Brooks displayed advanced technology in saddle construction. I found this article(PDF) in the Nov 24, 1933 edition of Cycling magazine. The Brooks piece was a part of a larger article about highlights of the show.

There are some interesting concepts here for Brooks wonks. I have never seen one of these saddles.

Interesting vocabulary:
“roadfarers” kitbags” “Champion Duralumin” “B.16 Champion” “castalumin formation” “automatic tensioning device” “fabric-cum-leather-cum-felt surfacing” “dome-headed rivet” “Plyflex” “constructional alteration”