Então, por exemplo, o source.list para o ubuntu Jaunty (9.04) ficaria assim:
deb http://old-releases.ubuntu.com/ubuntu/ jaunty main restricted deb http://old-releases.ubuntu.com/ubuntu/ jaunty-updates main restricted deb http://old-releases.ubuntu.com/ubuntu/ jaunty universe deb http://old-releases.ubuntu.com/ubuntu/ jaunty-updates universe deb http://old-releases.ubuntu.com/ubuntu/ jaunty multiverse deb http://old-releases.ubuntu.com/ubuntu/ jaunty-updates multiverse deb http://old-releases.ubuntu.com/ubuntu/ jaunty-security main restricted deb http://old-releases.ubuntu.com/ubuntu/ jaunty-security universe deb http://old-releases.ubuntu.com/ubuntu/ jaunty-security multiverse
Adapte à sua necessidade e seja feliz :)
