"PLEASE RETURN COVER" LABEL. 1937 envelope from Rose, Cornwall to Mousehole, Penzance with KGV ½d and 1d which have obviously been used before and with label "Please return the cover of this letter. It is required for Official purpose only...Head Postmaster of Truro 22 Feb 1937". On front ROSE/PERRANPORTH.CORNWALL datestamp 22 FE 37. Most unusual. (Ref 93974).