What makes you think it is made out of silver and why it could be Dutch silver? The bird cage lacks all the known Dutch hallmarks; the standard mark, being the Dutch Lion, assay office mark and a valid date letter. Sorry, the makers mark is not clear to me and if there are no more marks to be shown, I believe not Dutch. The Dutch hallmarks, if present, could be spread over the cage.
Just watched New Tricks and I hate to look at ghost marks. OK, the sword mark could make it Dutch or made in Belgium, if the maker’s mark reads; PF 228 in a rectangular. The maker’s mark could be for; Jans Pier Fennema, city of Bolsward (province of Friesland), mark used 1855/1888.