I’m not a Perl guru (although I consider myself a medium level wizard :)), and this last contest shows it. My entry for it was 4.6258 times longer than the shortest one submitted. :(. Some tips (maybe you can do better than me):

• Wrapping your head around Roman Numerals is hard. I suggest that in addition to the Wolfram research page, you also read this very useful page about the subject (found it through Wikipedia)
• The Perl::Squish module won’t do you any good. It may work for usual modules, but for my code it didn’t reduce it even by 1 byte. If you still want to use it, the code needed to run it is:
  

  use Perl::Squish;
  $s = Perl::Squish->new();
  $s->file 'infile.pl', 'outfile.pl';