Hallmarks on 18th century silver spoon

British Silver Reading Silver Hallmarks
1

I have recently acquired a Dutch table spoon, but I’m not really an expert on Dutch silver hallmarks of the 18th century.
Am I correct with the following interpretations of the hallmarks?

  1. First hallmark from the left: WS for Willem Schiff

  2. Second hallmark from the left: Letter N under ? (I cannot make out the symbol - it does not look like a crown) for Nijmegen (according to Tardy’s ‘International Hallmarks’)

  3. Third hallmark from the left: Double-headed eagle? under crown, also for Nijmegen (according to Tardy’s ‘International Hallmarks’) or does it indicate silver standard of .875? - like the Lion Rampant for other Dutch assay offices?

  4. Fourth hallmark from the left: Letter N under crown: Date letter?

  5. Fifth hallmark from the left: This looks like a Gothic letter in an oval. Is it a duty mark?

Thanks in advance for any information.
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