I’m not sure why you think this spoon is Dutch. To me, your spoon in the Thread or Filet pattern was made in Paris in 1781 of 950 standard silver. You show the silver standard / date letter mark of a crowned S for 1781, the charge mark of a crowned A used 1780-1789, and an export mark of a ewer for the same period.
The maker was Nicolas Gonthier. His mark was a crowned fleur-de-lys, two grains, initials NG and a crozier as the symbol. Gonthier had a long career. He apprenticed in 1738, and was received as a master on 24 December 1768. He was number 198 in terms of taxes paid by 1774, so a fairly prolific maker. He worked on the Pont du Change from 10 December 1781 until 1787, then he is known to have had an address on quai Pelletier from 1788-1793. He married Louise Royer on 13 March 1778.
In summary, your spoon was made in Paris in 1781 by Nicolas Gonthier.
See Nocq, v. 2, p. 265.
Hope this helps.