It could be Belgian (the mark on the left has an
A O O and one missing).
I found unregistrated Belgian marks and one of them had an
A O O 8, so the 8 could be the missing one).
The sauce boat could be made by the Wolfers Frères, influenced by "Japonisme" (=The Japanese influence on Western art since 1858’ by Siegfried Wichmann.)
Wolfers Frères = Wolfers was one of the most famous Belgian silversmith companies of the 19th century, its reputation comparable to those of Emile Puiforcat, Odiot or Aucoc in Paris, Garrard in London, and Tiffany or Gorham in America.
In the first half of the 19th century, three young German brothers, silversmiths Edouard, Guillaume and Louis Wolfers established two workshops in Brussels.
Source:
http://www.modernsilver.com/philippewolfers.htm" onclick="window.open(this.href);return false;