Hi Chris,
Thought I'd give you a hand to embed your photos.
The reason you are having difficulty identifying the marks is that they aren't Dutch. They are German Hanau pseudo marks. The maker is JD Schleissner and Sohne.
Please see here for more information and examples of your marks:
https://www.925-1000.com/Fgerman_hanau_marks_01.htmlCheers,
Steve

