Q57 January 2009   member 595 10 mils 1926 Oxen overprint. I purchased this stamp recently at a local stamp show. I noticed that there was a faint double overprint of the "1 0" as shown in the scan plus one other small black mark positioned where the tip of the "S" doubled overprint might be placed. This is not listed in either Nile Post or Balian. Has anybody seen this error before? Any feedback is appreciated.