That was such a feel-good fic; made me smile and sigh contentedly.
At the beginning, I was a bit afraid the guy who was stealing the plants might be Snape, but it was obvious fairly quickly that it wasn't him, or at least I really hoped it wasn't. I liked how you used Hermione's parents needing to get their memories back as a method for Snape regaining his memories.
So now a small segment of Muggles are going to be looking oddly at the statue of Sir Hans Sloane and wondering what is on the other side :-)