Well, I trimmed off the remaining curved lip on my patch panel…

Marked it with tape for a straight line…

Didn’t need to remove much.  What was left over minus the width of the cut-off disc:

I am really pleased with how it looks.  The left side still wants to pop-up so I might have to get a spare hand (to hold it down) when marking what to trim from the car.  I’m not planning to do any more trimming on the patch panel.  Just some final cuts from the car and then prepping the metal and welding it in…  Then there is the other side!