HONG KONG
Covers and stamps / Hong Kong / U.P.U,
HONG KONG: 1930s: International Reply Coupon, London type design, Proof for 40 c. imperforate in block of four, very fine unused, believed to be unique.
HONG KONG: 1930s: International Reply Coupon, London type design, Proof for 40 c. imperforate in block of four, very fine unused, believed to be unique.