https://www.ebay.com/itm/154724208422Decidedly less interesting than most; I guess whatever Apple engineer held onto it converted it to a 2/5 when the kits came out although it is still a prototype.
What I've been curious about for a bit is the mouse, which is serial 378. The thing is, this is the third or fourth mouse I've seen that claims to be #378. Are we sure the sticker on the bottom is actually a serial number and not something more mundane like an internal model number?