Shoot a roll on something — anything at all you desire, and just freeze it. I kept unopened rolls of Kodachrome from 1987 until 1997 when the last three went to the processor (Sydney, Australia): all perfect.

But I'm not optimistic at all of a re-emergence in Kodachrome processing — not with Kodak the way it is (and likely getting worse). Or with the rude march of digital.