Being bored last night I messed around with Photobucket to see what could fit in the Amity area. I used Forbidden Journeys Show Building. I also used Hogsmead with the assumption that Diagon Alley could be built to the same scale (they'd have to enlarge it much bigger then the movies depect). I kept most of the amity buildings as well as the original pathway as these would represent where the "Muggle" buildings in London would be placed to Hide Diagon alley behind them. The main enterance to Diagon Alley would be located on the south end of the area (there would be another "Muggle" building where you see the Hogwarts Express) with another entrance being placed at the north end near the Fear Factor stage. Although theres only one entrance to Diagon Alley in the books/movies it would be a crowded nightmare to only have 1 way in and 1 way out. Obviously the show building could be larger or smaller and shapped better to fit the land. But it goes to show there is quite a bit of room to work with.
Nice work, and it's amazing how much space is back there.