He left the building as it was...with the bare brick walls (reconstructing the walls where needed) and added the original painted plaster fragments whenever they were available (having been found in the rubble). He added new stairs, etc where needed and created a wonderful mix of old and new. When I first entered the Museum I wasn't quite sure what I was seeing, but once I got it...I loved it!
The Museum is wonderful but the best is that I actually saw-in person- Nefertiti! She is more beautiful than I imagined and like the Mona Lisa, photos just don't do her justice...but here are mine.