Brother Hal, you are correct - - the Mil Spec and the GI model are different. The Mil SPec has vastly superior sights than the GI model that I bought. Springfields website outlines the differences. It is curious that they chose such confusing names for these two models.
GI .45
http://www.springfield-armory.com/pr...-1911-GI.shtml
Mil Spec
http://www.springfield-armory.com/pr...-1911-ms.shtml