According to my sources at George Eastman House, there are on average 6 contacts each year by people determined to reproduce Autochromes. To date, no one has done it. This includes the people who own the original autochrome equipment.
Your comment is apt here. I would tend to agree. After all, the Autochrome is 'revealed' in patents, so why can't we do it today? Well, this emulsion is 'revealed' in patents too. I say good luck to anyone who wants to duplicate it. It would take an expert, reading about 2 dozen patents to get all of the information in-hand, and then the experimentation starts.