For msilib, 'int numbers' should just be 'ints' or 'integers'.
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For PC/winreg.c '''\
PyDoc_STRVAR(PyHKEY_Detach_doc,
"key.Detach() -> int\n"
...
"On 64 bit windows, the result of this function is a long integer");'''

This last line should be deleted rather than modified, as its only point is to override the signature declaration of returning int.
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I cannot vouch for this change:
-/* necessary to make sure types aren't coerced (e.g., int and long) */
+/* necessary to make sure types aren't coerced (e.g., float and complex) */
I presume you thought about it carefully in context.
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The rest of the changes look grammatically correct. I cannot be sure about the executable code changes.