They are 9 Br/I emulsions coated in thin layers with very specific sensitzing dyes used that adsorb to the grain and survive the process. Making them would be a pain, sensitizing them another pain, and coating them would be a miserable job. After the 6 - 8 layers needed, the yeild would be less than 20% IMHO due to defects.
OTOH, you can use a one shot 3 color camera and make 3 RGB positives that can be processed in each of the C/M/Y color developers of the Kodachrome process. Then you laminate all 3 together and you have a very nice transparency. Much easier.
On the plus side, either route would give you a 4x5 Kodachrome transparency! (At great expense in time and money)
...OTOH, you can use a one shot 3 color camera and make 3 RGB positives that can be processed in each of the C/M/Y color developers of the Kodachrome process. Then you laminate all 3 together and you have a very nice transparency. Much easier....PE
OK, I know the C/M/Y developers probably aren't available at my corner photo shop, but how hard are they really?
The availability of chemicals today is far superior to the past, and the availability of surplus equipment is also far better. Assuming that one has a fairly solid technical background - not really an unusual trait in the group that reads stuff here - there's not much I would put beyond the capabilities of a bunch of dedicated enthusiasts. It might not be all that economical, but if economy was all that I cared about I'd pitch every film camera I own out the door today and go completely digital. That's not who I am, nor who most of the other people here are either.
So, let's scheme this out shall we. After the gigantic discussions the past few weeks about Kodachrome and how to rescue it, this may be the answer. Just do it ourselves. After all, Sergei Mikhailovich Prokudin-Gorskii simply used 3 color separation and look at some of his stuff.
The developers are currently available and have been mentioned many times here on APUG. I don't have the reference, but they are basically color developers and couplers mixed to give C/M/Y images just like Kodachrome. Any B&W pan film can be used for exposure and lamination is simple.
I have no idea what the stability of the dye images are as I know nothing about the couplers chosen.
Perhaps someone would look up the reference here and post it or refer you to it.