I guess this is most likely directed to Photo Engineer but here goes:
I have a 5"x100' of Aerial MS Ektachrome from 1974. The film itself has survived all those years with grace, it can be exposed at 50ISO and developed into a negative without much problem. As you can guess, the emulsion will partially come off the substrate when ran through E6 - what survives are cyan highlights and a dash of magenta. Yellow floats off completely. And doing room temperature C41 (or ECN2 in my case) still results in a soft emulsion that is extremely easy to damage while wet. Even agitating the developer seems to cause damage.
Now, I experimented with 10ml of 37% formalin and 25g of soda ash dissolved in a liter of water (didn't have the sodium sulphate at hand), that hardened the emulsion plenty BUT as some of you may know, that ties up the magenta coupler, so no magenta dye is formed during development. I have studied the E4 formulas (here: http://www.kodak.com/global/en/professional/support/techPubs/cis111/cis111.pdf) for quite a bit now and I see that the aldehyde must be neutralized before the development and the hardening is done in an acidic environment.
My problem here is that I am short on cash most of the time and the process seems to rely on some specific chemicals (having a Kodak something something designation) and I am unable to mix up the right stuff. Could I theoretically make the goo I made earlier more acidic (acetic acid maybe?) and then neutralize it with it something more simple? It would be a shame to let that roll of film to waste, considering how well it has survived.
Thank you for your attention!
Let me preface this by saying that I don't know nearly as much about this as you do. That being said...
I acquired some E4 IR sheet film, and also have been wondering how to process. The consensus from discussions read in the archives here is that it should be possible to process them in E2 or E3 (E2 being far more common), since E4 is basically E2 with the neurotoxic reversal agent in place of the re-exposure.
However, I found a guy who processes E4 as negative with the C22 process. Much less toxic and less involved than either E2 or E4. So maybe that might be worth a try. Here's the link:
And here's a guy who does E2 film (that apparently could also be processed as E4) in a modified c41 process:
If you have either of these already, my apologies. Hope this helps, let me know how it all comes out!