[gentoo-soc] GLEP 25 + GLEP 9

Hello,

I am interested in proposing picking up where GLEP 9 and GLEP 25 left off and 
finally getting difference patches for portage distfiles working properly and 
implemented in such a way that they can become part of the official tree.
The proposal would address actual implementation of the above as well as 
modifying the various other tools that must use them such as "distfiles-clean" 
and portage itself of course.

Would this be worth proposing? I know that I am not the only one who would be 
very happy to finally see this make its way properly into Gentoo.
Which source repository should I submit a patch for if I want to propose this?