I already cope with different sizes of the debug and release (line 385):
ifndef _DEBUG
        /* padding hack.  8 byte extra length observed at
         * runtime, for 32 and 64 bits when not in _DEBUG
         */
        __int32 _padding[2];
#endif
This fixed a problem as reported in another defect.  But now you are 
saying that the struct size in Release is different for minor revisions 
of the dll?  Oh dear.
I wonder if we can just try both sizes...  But it might cause a 
segfault.
I had already assumed that the observed size difference was because the 
CRT sources were not in line with the actual minor version of the CRT.  
Obviously, this means that there are issues involved.

We could also simply redistribute the MSVCRT in python/bin, as we are 
allowed to.  This is how we solved similar issues when releasing EVE 
for various platforms.