Szechwan 30 variety, CSS 1518b, "Inverted Surcharge" on 1949 Silver Yuan West Szechwan surcharged as Registered Mail Unit stamps, $4,000 grey on SYS Shanghai Dah Tung 2nd print

Szechwan 30 variety, CSS 1518b, "Inverted Surcharge" on 1949 Silver Yuan West Szechwan surcharged as Registered Mail Unit stamps, $4,000 grey on SYS Shanghai Dah Tung 2nd print