I tried to install the adapters from Motorsports Hardware and had to discover that they were not 74.1mm to 72.56mm adapters, but instead 72.56mm to 74.1mm. So exactly the opposite of what I needed to install smaller 72.56mm hub wheels on the larger 74.1mm hubs found on the E70.
So I had my wheels machined to the larger diameter. I obtained three bids amounting to $280, $200 and $100 for all four wheels. I went with the $100 bid by a Reno machine shop using CNC machine tools. There are a number of videos on Youtube showing do-it-yourself methods using a router, but since I could not find an exact router bit for this application I decided to let a pro do it.