It fit me (34" bustline) quite well. It will require 2 yards of outer fabric, with or without nap, and 1 7/8 yards of lining.
Now what to make it in? I was originally thinking of cotton velvet in a color to coordinate with my day dresses. the sleeves will not accommodate the bulk of my day dress sleeves. After doing more research, it looks like jackets of this kind were not meant to go over other dresses anyway. The illustrations inevitably show them over a blouse, sometimes with a vest, and a skirt that is usually made of the same material. The original May 1863 instructions suggest making it out of cashmere,silk, or wool.
Here is an illustration from 1865 showing various jackets. It is from La Couturière Parisienne, one of the best sites I have found for researching high fashion from previous centuries. She has everything from paintings and fashion plates to actual patterns available there. This illustration is a couple of years beyond what I'm shooting for, but it fits with the other research I have done on this.
So, in addition to the usual dithering I have over color, I have to decide whether to make it in a heavier contrasting fabric, possibly to donate to the museum where I work weekends for the docents to wear. That would need to be easily cleaned, which limits my fabric and trim choices. Option 2 is to make it from silk and make a matching skirt. That would also require making a blouse. All that would be a much larger project that I had originally intended for this. Option 3 is to make it to wear to my day job at a archives library, which gives me more color choices, but would again limit the choices of fabric and trim. I'm leaning towards combining Options 1 & 3, making it for work, but also keeping in mind that I could use it with the costumes at the museum.