I got frustrated with trying to tune it, and set it aside. At one point I threatened to make it into a bass, and just leave the kalimba tines as sympathetic chines. Today, I got around to it: I used the rake handle as a through-neck, and put an old drawer.handle on the now-stripped back (masonite, no less) as a bridge.
I used an old furniture screw to mount a prototype "jingle" instrument on the top of the handle, to allow the beer-caps to ring when the stick is thumped to the floor or shaken.
I strung up the bass with eyebolts and weed-whacker line left over from my "doodle base" build. The two strings are tuned to a low G and the D below it (the root and dominant of the kalimba's diatonic scale). I also managed to get the kalimba tunable by screwing in a third screw in the center, allowing me to keep enough tension on the bar to keep already-tuned tines stable. I can play simple melodies on the kalimba with one hand, and pluck the bass strings as "drone" notes with the fingers holding the stick. To get other notes on the bass, I would need to turn it upside down and "fret" it against the handle like a washtub bass. I'm pretty happy with the funky, sculptural quality. Don't know that I will be playing out with it anywhere, but it has been a lot of fun to push it to completion.