Jon Rockway and I are working on a way to find old distributions easily, but it probably won't be done during the holidays. We're indexing all 9 Gb of BackPAN so you can search by module name and version to get to the right package. Some of those might still be on CPAN, but they might have been removed to clean up an author's directory.
For now you have to find the old distros on BackPAN. The easiest way to find them is to start in the current author's directory and look in the distros yourself. Bisect the list of distros until you find the one that you want. Watch out for distros that have the same module versions. The distro version isn't necessarily tied to any module version, and when it is, it's the version of a particular module, not all of the other ones that came with it.
The next trick after finding the right distro is to figure out if it works with the latest versions of its dependencies. We're working on that too so we can tell you which versions of its dependencies were current when that distro was released.
If you're using the latest version of my cpan script, you can use the -D switch to see the details of the latest version:
$ cpan -D Tie::Cylce
Tie::Cycle
----------------------------------------------------------
Cycle through a list of values via a scalar.
B/BD/BDFOY/Tie-Cycle-1.16.tar.gz
/usr/local/lib/perl5/site_perl/5.8.8/Tie/Cycle.pm
Installed: 1.15
CPAN: 1.16 Not up to date
brian d foy (BDFOY)
bdfoy@cpan.org