Martin, I found another description of a type called the M-23 ( also seen it labeled as M-23-A1), which is just a cardboard tube and must have weighed about 7 to 10 lbs. It sounds like it could be dropped out of a flare tube. It was primarily used at low altitude, so perhaps still not the right one.
https://books.google.com/books?id=aW...20tube&f=false
In the above link, discussing the cameras used, they had a type of electic eye that would fire the camera when the photoflash was detected.