I didn't realize that project was started four years ago.

Here's a small update…
I've cleaned the main board of the 12-in-1 game, and one thing quickly became apparent: whoever designed the PCB may have had modders in mind because almost all the wires connections are spaced 0.1" and all the connections are labeled!
I was able to solder pin headers for all the connections except the two wires for the battery/power supply. This will make a very neat installation inside the little cabinet.
The first photo is the main PCB with the "coin door" PCB, both upgraded to pin headers. The second photo shows where I plan to install the main PCB inside the Coleco case. If it's not clear from the photo, it will sit inside, on top of the battery compartment, maybe glued in place with two-sided adhesive foam.
There's one problem with the LCD display from the PS2 gamepad, I forgot to take notes about which wires does what when I dismantled it, but there's only 7 wires, 3 of which are near the headphone jacks, two which go to the power switch and two other which go to the PCB connected to the LCD panel (composite signal). I can easily see which one of the power wire is the ground, so the worst that should happen is a cross-wiring of the composite signal which should not be fatal to the electronics and easily switch around if needed.
And inside the case, where I had stored all the parts for the build, I found
four tiny microswitches that I even forgot I had. I was planning to build my own tiny joystick! With the help of either my Roland MDX-3 or my CNC64 project, I'll cut a tiny plastic block and make my own instead of buying that Grayhill 04A-B01. I'll probably base the design on the Seimitsu LS-32, which is more or less a sandwich of cut plates. I should be able to do something at least half-decent with my CNC. The 3rd, 4th and 5th photos are those microswitches, the last one being in a joystick pattern. The dimensions of the joystick, including the soldering tabs, should be around 40x40mm.
If the result is good enough, I could start making these tiny arcade joysticks for people who build tiny cabinets as an alternative to that Grayhill 04A-B01 joystick. Mine will be bigger, but as far as I know we currently have a void in our choices as far as size is concerned. It's either the very tiny 04A-B01 or a full-size Sanwa or Seimitsu joystick.
The two buttons will be the
all-black Sanwa SDM-20 I ordered from ArcadeShop.de a while back when I also ordered the all-white SDM-20 for my MVS-99-6 project.
Also, since the 12-in-1 joystick includes Pole Position, I'll try and add a tiny steering wheel to my control panel. The
LEGO Technics #4125213 would be a good part even if it doesn't look like the real Pole Position steering wheel, unless someone has a better idea? I could also try to cut my own on the CNC from thin aluminium but I doubt I would be able to make something even half-decent.