Barry, stdeb does much of what you're describing. (Try the "python setup.py sdist_dsc" command.)

I'm not particularly pleased with the stdeb codebase as it stands, but it does work reasonably well, and I'd like to see progress in this domain, but I'm afraid I don't understand the difference between what it offers and what you're proposing. I guess maybe you're not aware of the "sdist_dsc" distutils command it offers?

-Andrew