While continuing through the Women’s Institute Library of Dressmaking, they mention buttonhole cutters. Now, I could find no button hole cutters such as were pictured in the book.
I COULD find buttonhole scissors. While they look nothing like the picture above, the design is relatively straightforward, being a small pair of snips with a screw, which is used to set the depth of the cut. And while you can find them new on Amazon, the pair I located was a vintage pair off of an Etsy shop. And they were rusted and nasty and I knew I could never use them on fabric as they were. So I went to the Internet to see if old, rusty scissors can be revived. Happily, I found multiple websites that recommended using industrial strength vinegar to revive rusted tools.
Essentially, you soak the item in vinegar to several hours then use steel wool to scrub the rust off. And it worked! There wasn’t much actual scrubbing involved as the rusty just flaked off. And as a bonus, the steel wool sharpened the blades while I scrubbed, so that once they were dry, my buttonhole scissors were ready to use.
Of course, I video taped this whole process and posted it, for the TL; DR, here is the video: