Gambia 1905 KEVII Portuguese Colonial Specimen Trio

1905 PORTUGUESE COLONIAL RECEIVING AUTHORITY ARCHIVE SPECIMEN : KEVII Keyplate 5d, 7½d & 10d (SG 63,65&66). The three unused stamps regular UPU-distributed SPECIMEN overprinted and additionally handstamped "ULTRAMAR" in violet (by the Portuguese authorities prior to distribution to their overseas colonies as specimens). Suggestion tropicalisation, attractive trio. Scarce, interesting. See additional image below.