It appears to take some inspiration from the crown-sized Belgian 5 Franc coin (https://en.numista.com/catalogue/pieces276.html), just without the wreath and value and making the design elements a bit smaller. It isn't in the catalog though - so you can add it to the catalog if you'd like.
the coin is much smaller than a 5 fr Leopold II
it is made of copper or brass, it weighs 4.37 g and diameter = 23 mm.
hopefully someone knows more about this piece.
thank you in advance.
