I gave that a go.

FILE:
for my $file (@files) {
    my ($stamp) = $file =~ /dump.(.*)/;
    next FILE if $stamp > ($now - $start);
    $numfiles++;
    $/ = "\nMcDarren\t";
    open IN, '<', "$dir/$file" or die "Ack!:$!";
    my $data = <IN>;
    $/ = "\n";
    $data = <IN>;
    my ($level) = (split /\t/,$data)[2];
    next FILE if $level <= $currlevel;
    print "$file - $level";
    print "Processed $numfiles files (total files:$totalfiles)";
    exit;
}
[download]

Gives:

$ time perl ysth.pl
dump.1167332700 - 71
Processed 8764 files (total files:58154)
       39.55 real         2.35 user         0.80 sys
[download]

Note that I needed to make it skip the most recent 2 days of files as the game was restored yesterday.

Regards the xargs/egrep solution - that also works (with a bit of minor tweaking), but isn't any faster than any of the Perl solutions.

Thanks,
Darren :)