1910 Chinese Imperial Post "Express Letter" 10c grass-green, perforated 11, unsevered strip of four (folded between stamps in the middle), Dragon's head facing downward, Serial No.937, unused, v.f., extremely rare (Chan E2). Complete unused strips of four are exceptionally scarce because the first section (#1) was to remain in the Post Office receipt book (a similar strip was sold in our June 2021 sale, $14,000 hammer) (Cat No. E1) (Image)