I plan to resurrect my original design over the Christmas break.
The reason that I want to get back to the original design is its consistency and relative simplicity.

Duplicating the finally block for every exit from the try body might sound expensive, but it only increases the size of the bytecode by an estimated 0.4%.
 
Using statement counts as a proxy for bytecodes, I ran the code query https://lgtm.com/query/1505907426052/ over a range of open stack and other large projects. The size increase is in the range 0.26% to 0.44%
(Note that the statement counts include dependencies)

I plan to start from 
https://github.com/python/cpython/pull/2827/commits/693b9398b5fd202fa5864f9cc76fa1bc7f84f62e
as that adheres to the original design, but cleans up the code.
Antoine that is on your branch, are you OK with me appropriating it?