35mm to Brownie Box Adapter

This is part of an ongoing project which aims to refit an old Agfa "Brownie Box" camera to accept standard 35mm Film. I have been tinkering around with this Idea for years now, but was stymied by the problem of loading and unloading the undeveloped film without using a dark room...
Since I should have access to a 3D printer, soon, I figured it would be time to revisit this project once more in the hope of finding a solution that I could not envision using other production methods.
The idea beh