Interesting thread. I have a similar pistol that my father brought back from France during WWII. I have the original paperwork stating that it and a Beretta are war trophies. The pistol I have is a long barrel Izarra (means Star, I believe, in the Basque language) and was made as near as I can determine between 1914 and 1918 for the French military. If I can successfully post a photo, you'll notice that there's a "button" that's been added to the slide just above the safety. The French military required it to prevent accidental movement of the safety when holstering the weapon. Since your gun doesn't have this button, odds are against it being a French military weapon. But who knows.
I see you've also posted on the Spanish Pistol Board so here's my thread on the same board:
http://forums.gunboards.com/showthre...ghlight=izarra
I emailed the gentleman who has this site and he was very helpful with info on my pistol:
http://www.carbinesforcollectors.com/starpage2.html
Good info here:
http://www.star-firearms.com/firearms/guns/izarra/
And here:
http://www.catalogacionarmas.com/public/parte3cap6.pdf
And here:
http://www.forgottenweapons.com/othe...ns/eibar-ruby/