The North Australian Observation Unit was formed in early 1942 to patrol remote parts of Northern Australia. Part of the O'Donahoo Collection. See Cat 1992 for details of service for Arthur Raymond O'Donahoo, VX135349.1. & 2. Felt patch with mustard-yellow coloured lozenge shape next to a dark green lozenge shape. Grey/Khaki backing. 2. Has grey backing and is a smaller version of 1.o'donahoo collection, arthur raymond o'donahoo, northern australia observation unit, naou, ww2, colour patch