Identify the old silver arabic (Ottoman?) coin [opgelost]

Hello,

I need your help to identify.
Weight is 0,4, d=~15mm

Thank you.

I can see the ascension year AH 1168, which matches up to Selim III; diameter indicates it should be a 1 Para coin, like this one, but I am unsure as to the mint or regnal year.

Yes, the ascension year is AH 1168, which matches up to Osman III. He ruled for only three years. There are no regnal years for the coins of Osman III, but 'marks'. The mark on this coin is ba, با . The mint is Constantinople. Nice coin, as these are scarce.

Thank you a lot!