Just to wrap this specific question up, the ignition key can be completely taken apart, cleaned up, and re-assembled. It works like a champ after cleaning up all of the contacts inside with isopropyl alcohol...did not need to replace the cable after all. Will probably cancel my incoming order for the 2004+ switch and cable.
It's a little bit of a pain to get at the Torx T40 bolts at the bottom to get it out, but I was able to do it without removing the triple clamp, handlebars, etc. I used a long-ish 3/8 inch ratchet with a pivoting head so I could angle the handle up out of the body work, and slowly got it out. There are three security-keyed Torx screws holding the actual switch to the tumbler. Once those are out and you have the switch and cable free of the tumbler, it's pretty easy to pry the plastic base out of the housing along with all of the switch internals. Clean it up, pop it all back together, and re-install.