[GeoK]

Thank you for your input, I finally did after your question. They do mount, seat straight, and function, however visually when looking at the back of the steering wheel one leaves a slightly bigger gap than the other. My guess is that it is due to the padding ERA used to cover the back of the wheel.

After educating myself about ERA wheels (never too late...) I confirm that, similarly to your case, the donor wheel was not an M3 DCT wheel.

And for those who might have followed this thread, allow me to quote your reply from another thread:
“I ordered a custom wheel for my dct from Europe. To my surprise, what arrived was a manual transmission wheel that was significantly modified to work with dct. I could post some pictures. The internal structure for mounting the dct paddles is indeed there, deep inside the rubber/foam of the wheel.”