You can replicate Kodachrome very well using 3 color shots on B&W and then using a reversal C/M/Y development scheme. This has been often published. At the end, you bind all 3 together to get a finished slide. There are no tricks and no need to compound special formulas, you just make up what works. Leadly and Stegmeyer published this in the '40s.

And Rudi, I am aware of these two types of endeavor but what I am saying that there is a LOT of talk here and across APUG but little action among those able to do it. They talk, but they don't do.