I bought this coin last saturday since it seemed to be a mid 1800's, what checks out. By what I could gather it's 5 Para,1858/59, Abdülmecid I, struck in Constantinople, from the Ottoman Empire. What I couldn't find anything about is the counterstamp. There are many local counterstamps on Ottoman coins, mainly from greek islands that wanted to impede some coins from going back to the general circulation (the best info I found about, don't quote me on that), but I couldn't find any other that resembles this one. I'm not even sure if it's upside down in the picture...
My best guesses for the lettering so far are:
ΓΙΣλ (gama, iota, sigma, lambda)
ΠΣλ (pi, sigma, lambda)
Υ?



