Dollis Hill Dummy Stamp with 9.5mm Violet Phosphor 1965 and 1966 Trials

Dummy Stamps printed with two Violet phosphor bands (9.5mm) used as trials. This cover was originally posted in London on the 1st of January 1965 (The dummy stamp was then removed). The cover was then re-used in London on the 21st of January with the Dummy Stamp applied. The Dummy stamp is rouletted at base.Ex The Edward Klempka Collection who was the Author of the DOLLIS HILL FIND