That looks very neat Louis, good job!
I used to regularly fly a Flyer before I got my Zephyr. Of course it only had the junk SD monitor, with that DIN(?) plug feeding it both power and video. You can fix this problem non-destructively, if you're adamant of preserving the original state of the rig. Simply find a female for the power/video cable for the DIN plug, and then extract, from the respective pins, the power and video sources into what ever connector interface you need - I had a bullet plug for power, and, of course, a BNC plug for video.
I'd love to post a photo, but I don't think I ever took one, and obviously I haven't had access to this particular rig since I've had the Zephyr.
Also, I think there was always some instability somewhere along the signal path - most likely in the adapter cable itself that made a digital signal very unreliable. I was glad to see that idea worked in theory at least, and judging by your own solution, in practice as well, just depending on the workmanship.