These images were actually discovered by APUG member Anton Orlov, when he opened up a Jumelle Bellieni stereo camera he found at an L.A. area antique store. These cameras have a magazine that can hold several glass plates and apparently the previous owner stored a set of fully-developed plates in the camera before putting it away in storage, possibly to keep the plates from being damaged. It seems that the camera has remained in storage ever since.
Anton runs a rental darkroom facility here in San Diego called Rollov Film Center, and recently converted a school bus as a mobile darkroom facility to tour the country and spread the word about analog photography.
Something's wrong - actually a couple things are wrong. Those aren't stereo plates. The aircraft dates from probably the last year or two of WWI, so less than 100yrs. The bomb is late-ish, too.