I was expecting undeveloped film.
I've seen the product of WWII film that had stayed in camera since 1945, but from WWI would have been truly remarkable. But in this case it's not so surprising, I think. By the sound of it these were old glass negatives used as spacers in glass plate holders so that cut sheet film could be used. Seems this was a common habit over a long period. Folks like ourselves, in a way, struggling to keep on using older technologies in the face of that ubiquitous upstart, miniature film, (ie, 35mm).
I once found some developed glass negatives in the glass plate holders of a 1920's Voigtlander Vag. These must be 1950's.
and a detail of another:
The WWI shots are still a very nice find, though.
