The solution was two fold: Kenosis provided this solution, thnk U! 1. I needed to take out the /r in b/c my Perl is 5.8.8

print for map { s/\s+/$letter++ . ' '/er} @lines;
print for map { s/\s+/$letter++ . ' '/e; "$_\n" } @lines;
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2. I replaced

 my $it = natatime 5, <DATA>;
with
my $it = natatime 5, grep /\A\s{4}\d/, <DATA>;
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