45 deg. Erecting Image Diagonal Prism for Quantum 4

I was wondering if anyone knows of a 45 degree Erecting Image Diagonal that would fit the axial port on my Quantum 4? Or anything like a camera adapter that would fit. Seems to be a different size than I am used to and definitely don’t want to mess up the threads. Looks like that arm on the bottom dial would hit most anything you tried to put in there. Thanks for looking. 

There is no way to retrofit the mirror diagonal with any kind of prism. I have a camera adapter (Quantum option) that comes apart in two pieces. One piece closest to the rear port screws in. I then can slide in any kind of 1.25" accessory including erect image diagonal.

Thanks, 
I guess what I’m looking for is a camera adapter for a Quantum 4. I wonder if there is any present day camera adapter that will work in a 1977 telescope?

If I'm not mistaken if you thread off the erecting prism off the back of the cell the threaded attachment it goes onto is an m42 threaded attachment like old camera lenses. You could also go on cloudy nights as there is currently in the classics section a thread pertaining to the quantum for and there's a number of owners who have chimed in