Hi Trev,
Yes Dutch, period Kingdom of Holland 1807-1812 (French occupation), 10 Penningen or 833/1000 fineness, office mark the Greek cross for the assay office of
Zutphen, date letter
a used Juli 1807- February 1809. Maker's mark B.W.R for; Bernardus Warnerus. (van) Roessing(h), city of Zutphen, age in 1807 51 years. Registered 1787- around 1843.
For the (hall)marks see:
http://www.925-1000.com/forum/viewtopic.php?f=5&t=32028
NB Zwolle assay office (1807-1812) used Latin or Roman cross.
Best,
Peter