VERY FINE APPEARANCE. A RARE EXAMPLE OF THE 1917 12-CENT PERF 10 AT TOP OR BOTTOM. ONLY TWELVE USED EXAMPLES ARE KNOWN, AND THIS IS ONE OF ONLY FIVE EXAMPLES WITH A REGULAR CANCEL. A GREAT RARITY.
At a certain point during production one of the perforating wheels became defective. In the course of repairs part of one perforation wheel was inadvertently changed from Perf 11 to Perf 10. Based on the physical evidence of surviving copies, this was the nineteenth row of pins on the wheel.
Many examples of the Perf 10 on One Side rarities show transitional perfs from 10 to 11 or from 11 to 10. This is because the out-of-gauge perforation pins would frequently cross the span of more than one stamp, depending on where the wheel contacted the sheet.
The Perf 10 on One Side varieties span both the 1917 Washington-Franklin and 1922-23 Issues. It is interesting to note that, apart from the 2c, there is no duplication of denomination between the issues. This would seem to indicate that the improperly repaired wheel was in use for only a short period of time, as there was little overlap in production of the issues. Based on dates of issue of the basic stamps, this probably occurred early in 1923.
Our census of Scott 512b, available at our website at http://siegelauctions.com/dynamic/census/512b/512b.pdf , contains only twelve used and four unused examples of this rarity. For some reason none is well-centered. Seven of the twelve used examples have precancels. Only one of the five with regular cancel is confirmed as sound (no. 8), but it is off-center in two directions. Two others (nos. 2 and 3) need to be reexamined as they have very old certificates -- one is from around 1950. The example offered here has margins wider than most and should be considered a very desirable example of this rarity.
Census No. 512b-CAN-01. Ex Schilling, Zoellner and Blumenkopf. With 1950 and 1998 P.F. certificates.