Basically, as picture B (middle) shows, this is a Coppel (Solingen) made bayonet, that was produced in AH 1307 = AD 1889. As noted by Shipping Steel on the Turkish bayonets thread ( http://1914-1918.inv...pic=161354&st=0 ), page 7, post 167, it seems that Coppel only made M1887 bayonets, but I think that all the examples of these that he has seen to date were all made in 1887/1888? - I know he'll correct me if I am wrong on anything said so far!
But as a close look at this photo shows, along with an examination of pictures A (top) and C (bottom), the original muzzle ring of this M1887 has been cut off and replaced with a brazed-on piece, with the muzzle ring now set at 19,7 mm above the tang so that it could be fitted to a M1890 rifle...
The ingenuity and sense of economy practiced by the Turkish army in adapting existing bayonets to new weaponry never fails to amaze me, from the straightening and shortening of Peabody M 1874 Yataghan bayonets, to the 1950's practice of fitting spacers with a smaller dameter on the back of muzzle rings of 1935 pattern bayonets, but this case - fitting a new upper crossguard section - has to be one of the best examples of the practice!