A simple little Perl script that takes an epoch, and a regular expression that captures an epoch within a filename, then deletes said file.

trim-by-epoch.pl

#!/usr/bin/perl
use strict;
use Getopt::Long;

$|++;

my ( $cutoff, $re );

GetOptions (
        "regex=s" => \$re,
        "epoch=i" => \$cutoff,
) or die "Invalid arguments: $!";

die 'invalid epoch' unless ( $cutoff =~ /^\d+$/ );

while( <> ){
        chomp;

        if( $re and /$re/o and $1 < $cutoff and -e $_ ){
                print "$_\n" and unlink $_;
        }
}