18 Kreuzer orange in mixed franking with two values 6 Kreuzer blue as correctly franked franking on registered cover the 4. Weight step from "Stuttgart 1 May 1866" to Augsburg, 18 Kreuzer left perforation defects otherwise very fine, unsigned, photo expertize Thomas Heinrich BPP (2024) "as registered mail the 4. Weight step exceptional rare and with this franking combination an unique piece! "