1888/1891, OFFICIAL 'O.H.M.S.' ENVELOPES, group of 4 envelopes intended for UPU distribution, comprising 4d brown legal size envelope 'CROP REPORTS', c.t.o. triple oval "N.S.W"; furthermore three registered legal size envelopes with preprinted address 'Department of Public Instruction Sydney', i.a. 5d green with ovp 'SPECIMEN' and 6d violet & 6d carmine, both c.t.o. with triple oval "N.S.W". Scarce group in F/VF condition.