Hi David,

The silver-plated seal perhaps originated as a silver- plated teaspoon or letter opener.

Silver-plated teaspoon, finial to commemorate mobilization Sept. 1939 with the Dutch Lion

Silver-plated letter opener to commemorate mobilization Sept. 1939 with the Dutch Lion
For information about Dutch mobilization September 1939 see:
https://en.wikipedia.org/wiki/Military_ ... rld_War_IIYour seal does it have an inscription/monogram or is it just a base?
Peter