Tanganyika 1927 KGV Small Format Die Proofs Assembly

BRITISH MANDATE: 1927 KGV SMALL FORMAT DIE PROOFS in black for 5c, 10c, 15c, 20c, 25c, 30c, 50c, 40c & 75c frame plates (betw SG 93-101) each on glazed cards marked BEFORE HARDENING. VF, a rare assembly thus, exceedingly difficult to replicate.