Without a decent Internet connection I'm unable to check if my suggestion is sane or stupid, but have you looked at archive.debian.org?
(Sent from my phone. )
I have a linksys nslu2 running debian which due to a broken disk I wanted to reinstall however i've found out that the debian 5 installer is no longer supported http://www.cyrius.com/debian/nslu2/install.html and that 6 must be used via manual unpacking etc. I'm not worried about support and would like to use the old installer method http://web.archive.org/web/20100211143812/http://www.cyrius.com/debian/nslu2/install.html but the debian mirrors only have the up to date distros on them. How do I go about mirroring the old version with a suitable release file so I can point the installer to it?