There's the Barker and Llewellyn series by Will Thomas, which is set in Victorian England. Very clever. First one is called "Some Danger Involved."

For the period between WWI and WWII, there's the Maisie Dobbs series by Jaqueline Winspear (first novel is Maisie Dobbs).
There's also the Bess Crawford series by Charles Todd, which I've not read.

For another Holmes spin-off, Carole Douglas Nelson has a series which start Mrs. Godfrey Norton (aka Irene Adler). They're fun.

I'm assuming you've read the Thomas and Charlotte Pitt novels by Anne Perry?

(are you on Goodreads?)