Well I have one here somewhere, but I don't think a photo with a scale will be adequate to reproduce one.They are a relatively complex structure with very thin walls -- the originals were rather thin blackened sheet brass. There is also the issue of light seals on it to deal with. I suggest spending the $20 each to buy at least one cartridge from
Blue Moon (a sponsor here) so you can make direct detailed measurements. Expired film cartridges still show up on ePrey occasionally, often at wildly varying prices.
I have no experience or feel for how fine, detailed, and precise 3-D printing (as available to mere mortals) can get, but I wish you good luck with your project. I recently ran a purchased roll of Delta 100 through my Minox B just to try and see what it looked like with modern film. I've had the camera since the 1960s, but it has never captured my attention like I might have hoped when I bought it.