The viewing angle is very bad, I couldn't reach out enough until I discovered a way to append two dovetail plate together, but then the camera already hit the window frame so that I only got less than a few minutes of exposure, so I did a stack of 9 shots, each of 11s. Stretched crazily to show whatever possible. Just a test, by no means real attempt.
DBK with Fujinon 75mm f/1.8 wide open.
I also tried that Cosmicar 6mm, it's large enough to cover the whole Orion.