1965 10d, block of 18 + strip of 3, 6d wmk. sideways right

1965 10d purple, a block of 18 and a strip of 3, together with 6d watermark sideways right, on cutout from the reverse of an envelope, making up a total payment of 18 shillings Postage Due, cancelled in Dublin on January 9_^th, 1969, one month before the 1/- value was issued. Two stamps have corner faults, the others are sound. A spectacular piece. SG D11a var., D13, Hib. PD 11we, PD 13,