Guten Morgen, ich schreibe auf Englisch, weil es besser für mich ist.
Official letter (exempt for territorial tax due to the SNR and mark from Conselho de Saude Pública) sent from Lisbon, Portugal on January 29, 1857 to Stockholm. Transit mark from Badajoz in blue where it was placed in closed bag and dispatched via France and Belgium. “VERVIERS / 8 2 1 / COELN” trilinear mark in red and Boxed mark SPAIN also in red.
In Prussia, written in the back 8 Sgr for an unpaid letter coming from Portugal via Aachen up to 7.5g according to the postal convention between Spain and Prussia (4 Sgr for Spain, 3½ Sgr for France plus ½ for Belgium).
Then eventually, 3 Sgr added for transit in Prussia for a letter going to Sockholm, according to postal convention between Sweden OR Denmark and Prussia, resulting in 11 being written in the front.
Circular mark from Hamburg (8.2) and KDOPA / Hamburg (9.2). At the destination 1 Riksdaler written in the front, top left corner.
The circular mark in Hamburg is from February 9, 1857. At that time, the seaway was closed which means the letter had to go via Denmark and could not go direct from Stettin to Stockholm.
According to the postal convention between Prussia and Denmark (1853) a letter to Sweden by land would have a Denmark transit share of 2 Sgr and Sweden share of 2½ Sgr ie, a total of 4½ Sgr.
So, my question at the moment is if 15½ Sgr (11 Sgr + 4½ Sgr) would be equivalent to 48 Skillings (1 Rds)?
Or where I could find primary sources of information about the exchange rate between Sgr and Skillings around this date?
Danke