2 Kr. Small breast shield orange along with 7 Kr. Ultramarine in mixed franking with 3 pieces 3 Kr. Large shield carmine on correctly franked double heavy letter from single circle postmark "FRANKFURT A. M. 18 / 4 74" to London / England, stamps partly imbricating fixed and with strange glue mounted, except for one 3 Kr. Small defects, cover to the margins scuffed, in this kind scarce representation of the 18 Kr. Postage, decorative letter from the Brückmann correspondence, new photo expertize Krug BPP (2018) "unusual three colors mixed franking from known correspondence. "