You had me at the summary, and my sense of Utter Fangirl Squee only increased as I read.
I've been a Holmes enthusiast since I was a kid, (and wrote a small quasi-crossover myself several years ago), so I started with hope, which was richly rewarded.
Your grasp of Conan-Doyle's style is exact, and it was a pure delight to see the two worlds so deftly brought together. Then to have that delight sustained over the course of a satisfyingly long and intricate plot, was a rare treat indeed.
This is the sort of joy that's what fandom is all about. Thank you so much!