First, that piece looks pretty cool. I wish I could find something like that for the accord.
Second. Does the screen fit between the pieces on the side so it is flush with the back bar? Or does the back of the screen sit against the two pieces on the side?
Either way could you used the screw holes where the factory mounting slider was to mount a fabricated piece that allows it to screw into the dash mount. I hope my detailed CAD drawing doesnt throw you off.
If you have a vise, I would think it would be a pretty easy bend of a metal sheet.
Good luck, I hope I am addressing the problem.