From what I understand, Kodachrome requires high degree of quality control which is not that easy to achieve. It was even difficult for the labs who used to process it. And unless you have that QC, you will likely not see any of the "look" that made Kodachrome different. So if is that "look" you are looking for, I think you are in for a disappointment, particularly with the problems that are already being experienced, due to lack of expertise and resources.
Its more that the correct formula for mixing the developers is replicated, not an easy task without getting the original composition, which only Kodak knows. Having dye couplers is one thing, but the PH, mixing ratios of developer, couplers etc is cruical.
PE, Steve Frizza and Piratelogy will confirm this.
But once a working method is documented, it should be fairly reasonable to replicate the same results each time if the instructions are adhered to and the PH maintained etc.
I know Steve Frizza had the same problems as Piratelogy, and he spent hours of experimentation too to get it right, yes we may never ever be able to get it "identical" to that of genuine K-14 processing, but im confident that acceptable enough results will be eventually achieved.
The most important thing is to get the film through the chemicals ASAP after mixing, as they have a very short life, when the couplers oxidise, this was a huge effort in a large lab to test and maintain the chemistry as they constantly needed replenishing.
If anything, (albeit time consuming) for smaller one off runs of kodachrome processing, its probably easier to achieve consistent results, because a fresh batch is mixed and used (just the once) immediately without the need for replenishment.
I would imagine it would be very difficult to keep a large scale lab running, and the only way to make the processing viable was to have a large scale system running with constant replenishment and an on-hand chemist to maintain and monitor the chemistry.
