Thanks to Andy E. of Andy E.'s Photo Blog I have full Nikon D4 Photographic Dynamic Range (PDR) and Read Noise data.
The PDR is higher than my estimate, while the read noise is lower. This implies a higher Full Well Capacity (FWC) than I had guessed. Don't be surprised by the "lumpiness" of some of the data. The D4 does intermediate ISO values through a separate amplification and this leads to "jagged" results.