ONE OF ONLY TWO KNOWN UNFRAMED RED "TO PAY/2D/ONLY" MARKS; 21st July 1817 EL (some folds slightly reinforced) franked by the Duke of Sussex (King George III's 6th son - an abuse of privilege, being written by someone else) to Oxford with near fine orange oval "Two Py Poft/Unpaid/Greenwich" and black handstruck "2" on the front, beside a very fine unframed "TO PAY/2D/ONLY" mark (Jay L806; one of only two known, dated within three days of each other) in Red. One of the rarest of all London free mail marks, and an important Postage Due Exhibition item. Ex Dove and Feldman and sold in our Oct. 2001 sale for £550 Cross Reference: LONDON POSTAL HISTORY, POSTAGE DUE MARKS, OXFORDSHIRE, ROYALTY (Image)