open (FILE, "<" . $quotedfullelementpath) or die "Can't open file 
+$quotedfullelementpath:$!\n";
    while (<FILE>)
    {
      binmode(FILE);
      my $line1 = unpack("H*", $_);
      if ($line1 =~ /0d/)
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You have the binmode in the wrong place.    You have to use it right after the open and before the while loop.

    open (FILE, "<" . $quotedfullelementpath) or die "Can't open file 
+$quotedfullelementpath:$!\n";
    binmode(FILE);
    while (<FILE>)
    {
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Or you could set binmode from open:

    open (FILE, "<:raw" . $quotedfullelementpath) or die "Can't open f
+ile $quotedfullelementpath:$!\n";
    while (<FILE>)
    {
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Because you are using unpack you could be matching one byte that has a "0" nybble and the next byte that has a "d" nybble, for example "10d2".    You need to just search for the byte that has the value "\x0d":

      if (/\x0d/)
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