Yang EC136a - East China, 1947-49 Shantung hand surcharged in red by wooden chop in one vertical line (large characters, small yuan) on Chairman Mao $500 on $20

Yang EC136a - East China, 1947-49 Shantung hand surcharged in red by wooden chop in one vertical line (large characters, small yuan) on Chairman Mao $500 on $20