6 Kr. Medium blue, V. Issue, having bright colors outstanding quality with on all sides complete roulette, centric clear tied by railway mail single circle postmark "FRANKFURT A. M. - CASSEL railway mail 2 1 7 (1867) " - first mailbox emptying at the first day of validity Prussian postal stamps in the former postal area from Thurn and Taxis. With railway cancel (TPO) a very scarce and at the same time attractive cancellation from 1.7.1867, sentimental value! Photo expertize Sem BPP (2016) "perfect"