@edjones, like with almost every RPi project, these parts don’t exist… You have to build them yourself, or use whatever you have.
If you haven’t touched the stock cam module lens focus, it should be ok. Otherwise, focus it to infinity.
Start with a cut of black tube, about the same diameter as the screw mount on the clip, about 5-7 millimetres of length. Place this between the clip, with the camera module at the rear. The extension tube should be completely “light tight”. Prepare to adjust the length of the tube. It depends on many factors you will find out.
Check the plane of the cam module, if it’s wonky by even a degree, heavy vignetting will appear. A custom camera module mount plate would be nice. It could be as simple as piece of black plastic, with cuts for the cam module lens and the tiny connector, and screw holes, light tight.
Now, moving the parts carefully, you can start searching the “sweet spot” for the cam module lens. It has to be centered properly. I’m sure you will eventually get there.
A 3d printed adapter for this would be great!