I really enjoyed the story. I was surprised at the combo (I didn't read the character list completely so I thought it was another member of the Golden Trio :-) )
I think the way that you handled the entire older Lilly issue was done well. Watching Serverus change was a good thing too.
Yeah, I've only written one SS/HG story. I think there are way too many good stories out there with them and I just don't want to add to the cacaphony. I'm glad you liked the story. It was a bit of a stretch to bring Jethro Tull into the mix, and I"m glad it worked for you.