You could create your own lib directory (i.e. in your home directory) and install various versions of version.pm there. Then use

use lib '/home/me/lib';
...rest of script...
[download]

or perl -I/home/me/lib ... to have perl search your lib directory before the standard locations.

See perldoc perlmodinstall for details on how to install modules in your own directory - the key is using the PREFIX= option to Makefile.PL.

Creating a separate directory for version.pm makes it easy to uninstall it or to replace it with another version.