You my friend have a lot of patience. I've been following this all along and was hoping to hear a happy ending to it. That last picture would literally drive me insane looking down at that
As you said the units appear to be one off, why not get a quality shop to mock you up an exhaust. It would guarantee it actually fitting in all directions (up/down left/right), be literally the same thing, and cheaper.
Just finally chiming in here after a lot of reading. Love your car though and the clean OEM+ theme you have going on