My gut reaction as a collector is do not shoot any all matching WWI and earlier Luger (or any WWII, but to a lesser degree of concern for me
). I understand the desire to shoot these fabulous firearms...it is built into their design and purpose. But from a collector's point of view, you can only destroy the originality of an example once, there is no going back. If you absolutely must shoot your and your Dad's guns, go with the 1917...it is valuable, but to a much lesser extent than the 1914, and in the worst case, it can be replaced. In all likelihood the 1914 cannot.