Carlo was a French artist and illustrator of many spanking and BDSM novels in the 1930s. Below are his illustrations from the 1934 novel Dolorès Amazone (Dolores Amazon) by Alan Mac Clyde.
Some of these might not be everyone’s cup of tea as they are definitely outside of the “normal” spanko purist box, but I like the collection as a whole and would prefer not exclude any illustrations.
Smiles and Spanks, NaturallyGin.com
Smiles and Spanks 
These must have been extremely kinky for the time. BDSM isn’t really my thing, but I’m always intrigued by spanking machines.