OK here is a rough prototype.
Just trust me, its not as big/bulky as it looks.
The box contains the TCM fooling and unlock circuit. The switch is big enough so its easy to feel without looking, and has a positive enough "action" that you are not going to accidentally flip it if you hit a bump in the track or something.
The green LED lights up when the torque converter is actually locked. (not just when the TCM 'thinks' its locked)
I figure it was simplest to mount the switch and electronics/circuit all inside one box and mounting that to the shifter rather than having a small switch mount, then a separate box under the dash. The wire coming out of the back of the box goes directly to the TCM.
let me know what you guys think so I can start making these ASAP.
Ben