The intial inspiration was the hat worn by Rachel McAdams as Irene Adler in Sherlock Holmes (2009) directed by Guy Ritchie.
Here are some hats in the same style from the 1870's-1880's.
Hat made with fur, wool and silk ca, 1885, French
Straw hat, ca. 1886, America
1870's-1880's hat pattern by Wingeo
I have bought the 1870's - 1880's hat pattern by Wingeo. I don't think that the pattern is bad but the description is really very minimalistic. If you want to make a hat like this I would reccomend buying the Womens Victorian tall hat by Lyn McMasters or the 1880's buckram hat frame pattern by Truly Victorian. I am actually using the description from a Lyn McMasters hat pattern to make my hat.
Cutting the buckram
Buckram frame for the brim and top
Both sides of the brim have been covered with outer fabric.
Now putting ribbon on the brim to finish the edge.
The top has also been covered with the outer fabric.
There a lot of things going on in my life at this moment. Working on this hat and my other projects helps me unwind.