EDINBURGH WILLIAMSON NOT PAID MARKS; Pair with Nov. 1776 EL (file folds) to Edinburgh ex Maybole with circular rimless "PENNY POST NOT PAID.E." h.s. on rear and Nov. 1792 local EL (file folds) to Browns Square with scarce serpentine "NOT PAID" h.s. on rear. Scarce marks. (2 covers) Cross Reference: POSTAGE DUE MARKS, SCOTLAND (Image)