used -- 1918 on 1913-16 ½a. green, a pair with central c.d.s., the left-hand stamp with handstamp inverted and the right-hand stamp with handstamp omitted; scarce and unusual. S.G. O29var.

Details
used -- 1918 on 1913-16 ½a. green, a pair with central c.d.s., the left-hand stamp with handstamp inverted and the right-hand stamp with handstamp omitted; scarce and unusual. S.G. O29var.