BIAFRA 1968 (UNUSED) SG8 1968 SOVEREIGN BIAFRA opt 4d Leopards block of 30

1968 SOVEREIGN BIAFRA opt 4d Leopards block of 30 (5×6) being the upper half of a sheet with full margins and sheet numbers 0032247 and 38726 unmounted o.g. (hinged in margins). Minor bends and surface marks and marginal blemishes but an extremely scarce multiple. Only 70 sheets overprinted. Purchased from Stanley Gibbons (still on their card)