Well, I was browsing through the Antique Pattern Library (free, y’all!), checking to see if there were any new or previously-overlooked books, when I discovered this treasure!
What a truly epic H! I will definitely have to embroider myself a monogram with this someday. You can find the rest of the alphabet, plus some fancy borders, in the free online book Sajou, Dessins de Broderies, Album 612.