I bought an early Voightlander Brillant on Ebay last month. It is a nice early all metal one with a compur shutter and a Skopar lens. The added bonus was that there was a partly exposed roll of film inside!
The film was Ilford FP4 this film was revised to FP4+ in 1990 so the film must have been purchased prior to then.
The film was on frame 4 when I got the camera the wheel on the camera that works the frame counter had left a rusty deposit on the film. so it was exposed some time ago.
I developed the roll of film that day in Kodak X-Tol. I have found that developer works well on old ilford films.
Looking at the photographs it looks like this could be a high school chemistry lesson in progress, bring in an old camera and load some B&W film shoot some film and develop the pictures. I would say that the person that took these pictures turned up with there grandfathers old camera which takes 120 film, and the school did not have a developing tank for the film. so it stayed inside the camera.
The cameras that the other people are using are point and shoot jobs, I would guess that this film was exposed in the 1980's
The voigtlander Brillant that the film was inside is a very nice example I have cleaned its Skopar lens and cleaned the shutter I am in the process of running a film through the camera, The skoppar lenses are very sharp and I have had good results from my other Voightlander brillants that have this lens.