German States, Prussia Group of 4 Folded Letters:

1. Two covers: One cover from Breslau and the other from Vlotho, each franked with a single 3 Sg. Bister (Scott #20, Michel #18) and 3 Sg. gray-brown (Scott #20a, Michel #18), both tied with rectangular postmarks.
2. 1867 Berlin Registered Cover: Mixed franking of two 3 Sg. brown (Michel #17) and one 1 Sg. rose (Michel #20), all tied with a rectangular Registered handstamp in blue.
3. Commercial Airmail to Liverpool: Franked with a mixed franking of 2 Sg. and 3 Sg. (Michel Nos. 17 and 18).