Hi David, the wheels in the pictures are both sizes. You are correct that the fronts are 17’s and the backs are 18’s.
Another member wanted some info so I thought I would post some close up shots of the wheels.
I believe that the centers are different sizes but am not totally sure. I can’t check right now as the car had a few minor issues so it is at my friends shop.
I also want to say many thanks for the help in answering some of my questions along the way. It was greatly appreciated. Thanks again David.