This is actually a quesiton form a friend of mine-
he has a roll of old (probably 1940s) Kodachrome sitting about that was shot when it was new but is as of yet undeveloped. I'm fiarly sure that this CANNOT be processing in the K-14 process of today. If so, where can this be processed relatively inexpensively, or can it be done at home in a (modified) B&W neg. or reversal process? Rocky Mountain photo, I notice, will process it, but their price is, as usual, rather high ...

Also, my question, if the processes are indeed not interchangeable, what exactly are the differences between K12 & K14?