used Perf. 13, a mainly used range of shades including dull violet (33, three unused), blackish violet with four overprinted "SPECIMEN" (one imperforate) and royal purple (31 including a block of four); mostly fine with a number of dated examples. (135). Photo for selection

Details
used Perf. 13, a mainly used range of shades including dull violet (33, three unused), blackish violet with four overprinted "SPECIMEN" (one imperforate) and royal purple (31 including a block of four); mostly fine with a number of dated examples. (135). Photo for selection