3D modelling for fabrication is not an easy task if you're going beyond basic shapes, and getting a reliable 3D print to mate with existing items just adds another layer of complexity to the mix.
In all honesty you may have more luck taking this project to a Makerspace or similar and talking to people on dedicated Modelling/Printing forums.
I sadly don't have the camera gear you're looking to use, so I don't have a reference to go on to help build up a model.