Really inspiring project, Mats!
I think it will look great in black & gold! With the resoultion of PCB etching you could make some really intricate designs on the watchface.
How about using a piezo-sensor instead of a touch pad? I recently got some Stick'n'Find
devices, and when you get them they're in some low-power mode, and are woken by tapping them a couple of times. I've never used piezo-devices, so I don't know the details, but I think they generate voltage when tapped, so they could be energy efficient.
Another idea would be to have the LEDs on the bottommost PCB facing up, drill holes above the LEDs on the middle layer, and then etch away the copper on the bottom side of the clockface layer below numbers on the clockface to have the LEDs shine through. Would give a very clean dial. Hm, I wonder if light will shine through the black soldermask?
For my own use, I think I'd like more than 5 minute resolution. You could have three rings of LEDs, 60 for 1-minute resolution, 12 or a bit more for seconds and 24? for the hours. 10 pins can charlieplex
90 LEDs according to Wikipedia, so you wouldn't need a huge number of pins. Of course soldering 100 LEDs sounds tedious.
If I didn't have so many active projects of my own at the moment, I'd start making a watch like yours right away ;-)
Greetings from rainy Stockhom!