No reason not to introduce an additional “nodal slide rail” between the L-shaped bracket and the camera, and then to slide the camera backward on that, adjusting everything until the right point along the lens axis is located to intersect the rotation axis.
This could also be your quick-release point maybe, to take the camera on and off the assembly altogether, without upsetting the parallax adjustments for a given lens setup.
Started out doing photography at the age of 6 using an uncle's old 1940 kodak brownie box camera. At 15 years of age, I decided to buy my very own 1975 Praktica SLR camera. I now shoot with a Nikon D850. I do unpaid TFP and commercial paid work.