The one in Chicago is a IXc.
http://www.msichicago.org/whats-here/exhibits/u-505/story/the-first-exhibition/the-trip-to-chicago/
An interesting comparison, in both construction capacity and field of use...the type VII series was about 750 tons, the type IX series was about 900 tons.
In comparison, the typical US “fleet boat” of WW2 (Gato/Balao class) was around 1500 tons.