Hi.
The mark in the middle (crescent B) is
Repunzierung (re mark) introduced by the Emperor of Austria in 1806.
Letter
B stands for Prague assay office.
Most of the time it was not easy to identify Prague silversmiths.
13 is obviously Loth standard.
For more details see my Prague ladle here:
viewtopic.php?f=8&t=57035&p=184846&hilit=prague#p184846Regards