FROM THE SIR PERCIVAL DAVID COLLECTION), VERY FEW EXAMPLES OF THIS ERROR ARE KNOWN, AS IT IS POSSIBLE THAT IT WAS REMOVED/CORRECTED AFTER ITS EARLY DISCOVERY DURING THE FIRST RUN OF OVERPRINTING. In our auction records, we record only fifteen examples of this error which can be fully documented. Multiples containing the error are highly regarded. Aside from the complete sheet mentioned above, there are two blocks of four (one originally in the Beckeman collection and the other illustrated in Prize
Selections from Rocpex '81), this strip of three and three pairs recorded.