This needs a bump. The OP inspired me.
I have some expired 600 film in a Polaroid Sun camera that's not doing anything extraordinary for me. I probably have about five frames left in the camera. I'd like to try exposing some of these in a homemade pinhole camera. Would I be able to remove the pack from my camera (in my darkroom), remove the top frame, expose it in my pinhole camera, replace it in the pack and camera, and then eject it from the camera to develop it (again, all in the dark)? If the first one goes well, maybe I can do the others en masse. Thoughts?