Shaz ;

Contact with the exporter and learn who buy ton of that stuff. May be you can buy from the end user.
You can not predict the exact dyes from the book , my link cover that stuff. Sigma is the seller of much of that dyes. My link cover how you will dye the starch. One of the two reds is very expensive.
And most importantly , the problem is panchromatic emulsion. I learned from Photo Engineer , no emulsion sensitizer today does not match with the curves of autochrome graphs at the book.
So if you want to do the original autochrome , you must change the recipe at the book and the link.
Yes every chemical available except the sensitizers in the emulsion. May be book covers that but it is in french. What book suggest for the sensitizers ? Please share .

Thank you ,