1826 EL with BELFAST mileage and Ir.+ Br. rate calculation

1826 Entire Letter from Belfast to Edinburgh with fine circular BELFAST / 80 mileage without ornaments just touched by Edinburgh PAID, manuscript post paid and with small boxed P.PAID (F/K 296) in brown, lower left with itemised calculation of the rate in red: Ir- 4 / Br- 2/4½ / 2/8½, reverse with almost fine TOO LATE of Belfast.
Despite slight filing faults, a fine and scarce item showing the full rate calculation.