1840 EL with Mountmellick PP and PAID AT

1840 Entire to London manuscript "2" in black and erroneously stamped with a very fine boxed PAID AT / MOUNTMELLICK in bright blue, this corrected with a very precisely overstruck MOUNTMELLICK / PENNY POST also in bright blue, both well clear of the central filing fold, backstamped with matching blue cds. Attractive and decorative, most unusual.