GUATEMALA. Sc.4b. 1874 (Nov. 26th). Cover to LONDON from GUATEMALA CITY. GUATEMALA despatch in blue and franked by the only known used example of the 1871 20 c. blue ERROR OF COLOUR tied by ´1´ handstampa of Guatemala in black. Three line dated PANAMA-TRANSIT handstamp in black and LONDON FOREIGN BRANCH cds (Jan 13th 1874) at upper right over-struck with 1/6 (one shilling and six pence) charge marking. Part of the address restored. Unique and extraordinary cover. Signed Block and Cert. P.F. (2001). Ex. HUBBARD and LANGE.