According to the authors of the Bust Dime I.D Guide, an unused 1809 dime was used to strike this issue. The digits 11 were punched over 09 in the date, and this resulted in the 1811/09 overdate. The reverse is exactly the same as used in 1809. What I like about this date are the prominent breaks which develop in the reverse die. These are clearly evident on two of the examples in my collection. Again, according to the authors of the I.D guide, the reverse die broke very quickly so that examples w/o reverse breaks are very rare. I believe the example on the lower left shows no (or only very faint) breaks. Late die state examples show a deep clash on the obverse field and bulging above the cap, and often appear damaged. This description from the Guide seems to fit the example at the top. I would appreciate your comments here. Approximately 250-350 examples of the 1811/09 dime are estimated to exist.