, fresh with large part original gum, the centre stamp remaining unmounted. A very rare and spectacular showpiece and unique in this form. R.P.S. Certificate (1932). S.G. 54a, 54d; £3,850+. Photo" /> unused Block Larger Than four A marginal block of nine from the foot of the sheet, the centre stamp with variety<I> "Portectorate"</I>, fresh with large part original gum, the centre stamp remaining unmounted. A very rare and spectacular showpiece and unique in this form. R.P.S. Certificate (1932). S.G. 54a, 54d; £3,850+. Photo | Christie's