Akira, thank you for sharing your efforts to make the two images look similar. Your post processed Z6 image does look much closer to the original 1DX image. But even after your adjustments, the yellows/greens/reds of the D1x CCD image still look (to my eyes) different than those colors in the processed Z6 image. Now, which version an individual prefers is up to the individual. For me, I the yellows/greens/reds of the 1DX still look a bit "richer" to my eyes.
Bruce, one thing to consider is that my computer monitor is just a generic one and not dedicated or calibrated for the image processing.
That said, it should be easy to make the color of Z6 image "richer" even processed from JPEG which is a lossily (sic!) compressed 8 bit data, as opposed to an original 14 bit RAW file. In this case, I was trying to make it closer to the one shot with D1X.
By the way, I'm curious about the potential to render the gradation of D1X sensor. For example, I wonder how it can tackle the rendition of the dawn gradient between orange area around the rising sun and the blue area of the sky?
I think the comparison is similar to that of analog signal on LP records and digital ones on CD. The dynamic range of the latter is clearly much wider than that of the former.