Ezio: yes. Once I have written a working-directory diff to a file for upload (non-trivial on Windows), 'Import' is as easy to use as Graft and as far as I know, the result when successful is the same. I know I 'should' learn to use kdiff3 effectively, but it seldom works right for me, and the live repository is the wrong place to learn by failure. (This gives me an idea for another forum.)

A third always correct import substitution pair:
import tkinter.simpledialog as tkSimpleDialog <-> import tkSimpleDialog

I am not sure if a script will be used until I try one. I do not know anything about writing extensions. A lists of Idle-specific conversions may be enough.