A day late and....
Remember the phrase "a day late and a dollar short"? Well, tonight I sorta got to see it in action. I bought a big batch of expired film from someone--including a LOT of Kodachrome. Kodachrome 25, 64...even some 120. I did see that it still seems to sell on fleabay--collectors? I sure hope people aren't buying it, shooting it and then getting disappointed when they try to get it processed!
You can process it as a black and white film.
You might like to try these guys
They process non-standard films and on their website they have a banner saying "Kodachrome is not dead... only sleeping (more soon!)".
You have to click past the "closed for holidays" page - it's on the main home page. NB that I have no personal experience with them.
There's an expression in legal circles " caveat emptor",(let the buyer beware) if the unwitting buy it without knowing there's no processing service available I'm afraid it's their lookout for not keeping informed before they buy it, not the sellers duty to inform them.