Damn! This was positively brilliant. The time you spent on the details is so clearly evident in everything. I particularly love the voice of the piece and the tone it sets. Victorian England shines through every description and makes it so easy to visualize the setting. I really felt like I was reading something from the late 19th century rather than something written today, and for that I most heartily congratulate you.
I loved you characterizations of Harry, Severus, and Albus (and I must confess that I saw a bit of Seamus in Nolan, so I loved him, too). Albus was especially lovely, interfering in a completely non-assuming way, and looking out for both his boys.
Again, this was brilliantly researched and written.