It is not really that simple. Some classes of ships were built to the same plans, but having been built at different yards, they differed in subtle ways. Other changes in classes may be developmental or budgetary.
According to NAVSOURCE, the DL1 Norfolk was a one-off experimental Destroyer Leader (i.e. flotilla flagship) built on an Atlanta cruiser hull. It was found to be too expensive so no follow-ons were ordered. http://www.navsource.org/archives/05/0201.htm
The Mitscher-class were purpose built on hulls of new design. They differ in weapon & sensor layout from the DL1 class. Loose Cannon makes a 1:700 scale resin & brass Mitscher-class DL
http://home.earthlink.net/~loosecannonproductions/Kit16.html