It is a very long story why they called it "Jewish Medals" but let me try to explain you shortly.
In 1908 , it was Sultan II.Abdulhamid period , Sultan declare the 2nd. constitutional monarchy (Mesrutiyet) in Ottoman Empire and it was a very big news for the public.
As we look like the modernism and right to the Non-Christians in Ottoman Empire in that period , it was totally a celebration and happiness in the empire.
I n that period , this happiness was visible in the flags , post cards , handkerchiefs and even in the custom made medals. But why they called those medals as "Jewish Medals " ?
Because if we look to the Sultan Mehmed IV period , in 1600 years , in Selanik (In Greece Now) there was a jewish Origin Sebatay Levi and his followers have been made Muslim , forced to change their religion
because of this , their execution is canceled and they were forgiven by the Sultan .
When we looked to the public under the II.Mesrutiyet in 1908 , II.Abdulhamid period , we can notice that all the unvisible forces and those people was "Sebatays" .
That is why , all the Mesrutiyet lovers called that medals as Jewish Medals and that name came to our days ...
Hope it helps ,
Avsar IBAR