I know of no one doing successful work on Autochromes. I see the results at that web site and I can say that they look nothing like the Autochromes I have in my posession and none that I have seen at exhibits. This is apart from coating flaws which I expect in this type of work.
I have been told by respected workers in the field that there were parts of the process that were not documented, and were "trade secrets", not Immaculate Conception! There is a difference. These trade secrets involve the use of that black pigment and the formation of lenticules out of the starch grains under pressure. There were apparently several more steps that were also omitted from the published documentation. People I know of have actually visited the site where the last of their machines is preserved and no one there knew how to operate the equipment, nor was there any documentation beyond the patents that the brothers published.
I guess it is not impossible, but very very difficult, and this person has a long way to go to get to the level of the original. I don't want to discourage anyone, but I personally am not going to work on this approach as it is far to difficult. Remember, an appendix can be removed via the mouth. Difficult but doable. There are easier ways to remove an appendix just as there are easier ways to achieve color.
My belief is that dye bleach is probably a better approach. I would also like to add that doing a Dufay type color material is rather easy and straightforward. I have seen it done.
Best wishes to those who wish to experiment on either approach.