U117 3.5p olive-grey OCP/DEX off-white paper greenish tint dextrin gum BLOCK

1971 3 1/2p olive-grey in block of four the scarce off-white paper on greenish tint dextrin gum variety (OCP/DEX). Normally found with the brownish PVA gum. Very distinctive. (Spec U117 cat 680 pounds) U/M Ex Mike Holt Stock