FINE. ONLY FIFTEEN GENUINE USED MULTIPLES OF THE 10-CENT HORIZONTAL COIL, SCOTT 356, ARE RECORDED.
According to Johl (Volume 1, page 181), only 10,000 of the 10c Washington coil stamp were issued. They were made especially for a New York firm to send out advertising samples, similar to the 3c Orangeburg coil. Only a few rolls were sold to the firm, and the remaining rolls were distributed to some of the large post offices across the country. Dealers acquired several rolls, but because most contemporary collectors did not collect coils, many were used and destroyed.
Our census of Scott No. 356 in used multiples, available at https://siegelauctions.com/census/US/Scott/356 , contains 15 pairs, one strip of four and two strips of three. Four of the extant used pairs originated on the same cover, which was prepared by Henry Hammelman and mailed in August 1911 from Washington D.C. (this pair was positions 8 and 9 from the strip of 11 on that cover). A guide line pair has been certified as genuine, but the cancel needs to be reexamined to see if it is one of the fakes produced during the last 25 years.
Census No. 356-CAN-PR-14. Ex Curtis. With 1960, 2000 and 2015 P.F. certificates (F-VF 75). With 2016 P.S.E. certificate (F 70; SMQ $5,000.00). This is the only graded used pair of Scott 356 in the P.S.E. Population Report