I'm not against keeping the old package, but there are two things:
* We need to ask sysadmins team, because this means a lot of extra disk space.
I'm not averse to hosting elsewhere, I just know Pg infra likes to keep control where they can.
* Building older packages is not that hard with the RPMs as you know -- just change the version number, and run make rpm11 (or whatever). I'm not sure that keeping the old packages are worth the hassle.
Unfortunately that's not useful. You need *exactly matching* debuginfo packages for the same build-IDs. You can't just rebuild the suite and extract the debuginfo packages to install on another host.