Old versions are easy to find.

What do you mean by "easy"? To me easy means a simple web search for something like "old versions of Perl" and it appears there on the first page. I realize I could find the source without too much trouble.

What do you mean by "a repository"? Just a location where the distribution tar-balls are available or a location that has binary packages for your system?

Since the topic is the OP's compiled version I was referring to compiled versions. But I could have been more clear.

The only good reason I see for...

Does this mean you didn't like my guesses for a purpose? :)