Small Disposable stanley blade / scalpel / knife to cut plastic shell neatly
Flatbladed Screwdriver - the wannabe chisel
Hammer - Just to get the 'chisel' into the first bits of the wood, after that didnt really use it much
Guitar Touchpad Finishing
Black Video Case - Cut a square, made adjusments, made a hole, screwed it on.. an it did the job.
Long headed drawing pins - Great for temperarily fixing anything that would usually need screws to mount (PCB, DB9 connector, even the cover I guess but I had screws handy).
Black Felt Tip - Given the state of me guitar, a decent way to cover the odd scratches
Solder - YOU NEED THIN SOLDER for the PCB mods - Really, unless youre really good, I used probably the thinnest I could imagine you can get it on a wire with (by hand anyway). For the LED circuit, i just fished up big dollops of this fat stuff and dumped it on. Not very professional but hey.
Cardboard - PCB's are a bitch to make properly, and really unneccesary for a few LED's. It'd probably work just as well without any sorta board, just loose components secured down somehow, but I prefer the card PCB, tis also handy for writing on the card your circuit diagram so its not confusing.
Elastic Bands - These were handy for securing stuff down that couldn't be easily mounted. Electric tape did little since its all hacked wood, so I just double looped the bands tightly, and pinned either end down with the pins. Like the battery, or wiring.
Some sandpaper helped, along with various implementations of electric insulation tape.
It depends what you're going for. Personally, I think the KP Body benefits from looking throwntogether and cut down. I mean, a window showing the divine korg circuitry, nicely lit looks pretty good, then with a clearly homemade computer serial port shoved on looks pretty neat no matter how dossed together it is.