I've spent some time searching for Ilfochrome recipes on APUG and here is what I found so far:
- I found this thread where a lot of chemistry is thrown around. Unfortunately brookse never posted a specific recipe, but he seems to have one.
- Here is a thread with some more info and a recipe which is said to work poorly.
- Here is another thread with a recipe. And another one. And one more.
- A number of threads recommend Dr. Beers developer to replace the Ilfochrome dev. Here is the recipe.
- Following the advice in these threads I searched for "dye bleach ciba patent" and boom, a long list of patents (like this one and that one from EK) describing dye bleaches and referencing other patents on that topic.
A long list of odd ball (to me) chemistry is mentioned but some are obtainable from Sigma Aldrich: 2,3-Dimethylquinoxaline, 2-hydroxy-3,6,7-trimethylquinoxaline, Sodium 3-nitrobenzenesulfonate, Phenazine, Quinoline and N,N-Dimethyl-4-nitrosoaniline.