This should get a special award for best use of Draco in a Snarry fic. Who else could get away with living stealth in Regency England? Who ELSE would Harry turn to for an education in drag, and in passing? *cackles madly*
It was a sad situation that Snape felt forced into marriage, and even sadder that he felt that the only way he could get married was to entrap someone. But it's to your credit as a writer that that fundamentally tragic situation really didn't bring down the overall mood of the story.
I loved poor Harry's stumbles in trying to fit in, and I really loved Snape's reaction when the inevitable happened and he found out.
I was extremely impressed with the accuracy of the setting, its fashions, mores and language. You've clearly put a tremendous amount of research into this story, and it shows!