I cheated on the building both versions. I had 32 bit python installed and with the help of a colleague got hold of the installed files for the 64 bit version. I noticed that distutils was looking for the 64bit files in new_lib = os.path.join(sys.exec_prefix, 'PCbuild'). However, even though I had the files there the loader was missing them and trying to use the earlier lib specs. Experimenting with the command line led to the desire to prioritize the amd4 lib specification ie use insert instead of append for library_dirs. After this patch things do seem to work, but perhaps there's a better fix that removes/moves the 32 bit libs in some way. However, given that I am building the exes with a 32 bit python I suppose it's natural for distutils to assume we need the 32 bit libs.