It was me. Saw an amazing CL65 for sale and noticed that it didn't have the V12 Biturbo.
I emailed the seller and he queried it with MB, they couldn't come up with a satisfactory answer. He had it from new and knew he hadn't changed the unit. He said as they are so rare he had never seen another 65, so until I mentioned it he wasn't aware that some had the V12 on the speedo .Like James he was disappointed.