Thanks for this reply, the question is still bugging me and I’m glad to see it’s gotten to other people too.
That picture of the Requin definitely fits the photo a lot better than anything else I’ve seen.
But as far as I can tell, it’s an older picture, showing the ship in 1892. These pictures from mid-1915 and 1916 show her without the rear crow’s nest and lacking the tripod style masts.
They are later pictures so there is the possibility the ship underwent some refitting between them, especially as that original picture is ambiguously dated. But this just further confuses the whole bloody question.
Inflexible bombarded Ottoman positions on Gallipoli in February and March 1915 before before she was damaged by Ottoman gunfire and a mine. The ship then underwent repairs that lasted until June. This dates the photo as one of three days, 19 February, 15 March or 18 March.