Do you mean next rather than last? Also, the OUT handle, while possible, looks fishy being read. A non-# character class will take care of the rest:

while (<OUT>) {
    push(@hold1, $1) && next if (m/(\w+\.bld):\d+:[^#]*$/);
 }
 my $hold11 = join(' ', @hold1);
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After Compline,
Zaxo