Hi Mischal, welcome to the forum.
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I believe the maker's mark could read
G.Z. in rectangle with rounded corners for: Johannes Albertus Adolf Gerritsen registered in Amsterdam & Zeist 1866-1908 and this particular mark used 1906-?1908. The other small mark is the Dutch sword mark.
Standard mark for; small work silver minimum 833 fineness= 83.3% pure silver and used on small work without date letter and office mark and in combination with maker's mark.
Peter.