I've been making prints from original WWII b&w negatives... and that stuff is poor enough quality! I'm doing good to get anything that resembles much the neg., and I don't know how they did it then. I really don't know how they did it in WWI, but certainly the film then was of even poorer quality. I doubt any two prints from the same negative under the same controllable conditions really looked the same. Maybe if someone finds a hand-colored photo...?
and that's my $.02
Air Gecko