I found some splendid, soft, heathered, cream-and-light brown wool cloth from an Etsy vendor that should be perfect for the purpose--a picture of the cloth can be seen to the left. As usual, click on the image for a larger version that gives a better view of the weave.
Susanna Broomé's pattern indicates that because the top of the stocking is not closed in the center, the socks need to be worn with leg wrappings or puttees. I'm not sure if that's true if I wear them with boots that come up a little way on my leg. I need to think about that some more. This should be a quick project to make, though. I probably will finish it in a few weeks at most.