1967 4d Wild Flowers MISSING AGATE. Four og singles all showing this VERY RARE ERROR. All with slight gum disturbance - see note in Pierron who states they were found by several lady pensioners in the West Country with most stuck to postcards before error was noticed. SG cat £18,000 as singles (SG717pd:SG718pd:SG719pd:SG720pd). (Ref 69255).