I always harp on how transformed the Old North neighborhood of St. Louis is. I've never seen such building restorations before! Even though basically reconstructed, they retain their historic look and feel.
1211-15 North Market Before
And After:
Source: Old North blog
Same buildings as above, post-facade repair but pre-roof.
And After:
Source: Built St. Louis
Blair/Clinton Intersection - December 2002 (Before A)
Blair/Clinton Intersection - November 2005 (Before B)
Blair/Clinton Intersection - September 2006 (After)
Source: Built St. Louis
And others:
Source:
Old North blog