A nice piece.
More interesting, not described in Kopicki and in CNG, a variant with the abbreviation MOIIE
Obverse: in the pearl rim the coat of arms of Gdansk, in the outer rim the legend:
MOIIE○CIVIT○DAI;
Reverse: in the pearl rim a shield with a crowned eagle, in the outer rim legend:
KASIMIRVS○REX○P;
Silver, diameter 19 mm, weight 1.09 g.