COLOMBIA/GUATEMALA - UNPAID MAIL TO FRANCE; Pair with 2 Jan. 1879 unpaid env. to Paris with very fine blue "T/1-10" all-in-one mark on the front overlapping a very fine "CARTHAGENA/A" British P.O. c.d.s. (showing "9" for "79" Error), having a "16" (decimes) arrival charge); plus similar 31 Aug. 1869 EL ex Guatemala to Paris "Via Panama" with a partial scarce blue 2-ring "CORREOS/GUATEMALA" c.d.s. plus that P.O.'s fine red boxed "FRANCO" on the front, along with a v. fine small British P.O. "A/COLON" c.d.s., an overstruck framed "GB/1F60c" accountancy mark and a "10" (decimes) arrival charge-mark. Scarce pair. (2 covers) Cross Reference: FRANCE, POSTAGE DUE STAMPS & COVERS, GUATEMALA, ACCOUNTANCY MARKS (Image)