https://www.ifixit.com/Teardown/Nintendo+Wii+Teardown/812
https://guide-images.cdn.ifixit.com/igi/ewv3yZPOujCRpKEj.hug...
That's it. And they didn't include the controller ports and other bits. For instance, I don't think it has Bluetooth or WiFi antennas, so it can't connect to Wiimotes or a network.
So if you wanted all of that back, it would be a little bigger. But not by much. Probably the size of the Game Boy Advance in the picture. If that.
But if all you wanted was Smash Bros on a keychain, here you go.
The person who came up with that idea, Johnny Lee¹, went on to work on the xbox and I believe was also involved in development of the Kinect.
You can use any two sources of infrared light instead!
So you can replace it with candles as they emite infrared light as well!
Turns out all the smarts are in the controllers, the bar is just there to show a couple of fixed points for positioning.
Also man do I feel old - coming up on 15-20 years since that and I actually remember HN discussion about it from the earlier days.