First you might not want to have your import and something else on the same line. Always put your imports before whatever calls to a function your are making!
import clr
import wpf
clr.AddReference('IronPython.wpf')
and I believe your file should be in the same directory for .Addreference() to locate it. as far as I know, the latest IronPython 2.7 should come prepackaged with wpf, but then again your version might differ. I would recommend to update to the latest, or download the modules you are missing and drop them in the IronPython repository at their appropriate location!
Hope this helps!