Thanks, Genghis - I think that 695 really is the diameter; a bit of educated guesswork makes me think that the propeller is from a Cri-Cri, which would presumably make it a rather unusual propeller. This is backed up by Google - a search for the numbers in question comes up with "Two-bladed composite MC 695 - 200 - 103" on a page called "Caractéristiques du CRICRI".