Heinrich Köhler 383rd Auction – Day 8 Special Catalogue: German States: Bavaria from 1849 – Auction of 'Missed Opportunities' – Collections – The ERIVAN Collection – 11th Auction

1831, "frco. Greifswald" script-L1 and Ra3 "K.S.N.P.C Greifswald" (tiny dabbed) on front and reverseon a folded cover from Christiana, with adjacent franking mark "STRÖMSTADT 21/4" to Lübeck, for the Prussian routestamped in red chalk "4", fine
Reference: "Schiffspost im Nordsee und Ostseeraum", page 69, (Richard Frick, 1981)