Little Medieval Coin

I have this little coin, but I am not sure what it is.
looks silver, 0,5gr , 1,73mm
Some possibilities:

Holy Roman empire
Frederick the Handsome (or the Fair) (1314-1330)
Pfennig, silver
6-pointed star

or:
Ottokar II. of Bohemia (1251-1276)
Pfennig (Silver)
Mint city: Vienna
Obv: 6-pointed star with clover leafs in the angles.
Rev: Embossing traces

or:
Ottokar II. of Bohemia, 1251-1276.
Pfennig, Vienna mint.
Obv.: 6-pointed star, a clover in each angle.
Rev.: Crowned head facing.

or
Ottokar II. von Böhmen, 1251-1276.
Pfennig, Vienna.
Obv.: 6-pointed star, lis in each angle.
Rev.: head of ruler, facing, border of stars




Any help would be welcome, I have no catalogs of that period