if there isnt additional chip visible i would try (in case there are so many lines connected) to find out how it is wired.
I would simply take a 3.3 V power source and start from 1-GND, 2-Power, then 3 Power etc. trying out ;)
Looks like normal 5 pieces of 7 Segment Displays -the middle could show only : or /
Or a (so named) 4 and a half Display
Or could you get the electronic from it from the clock ?
Maybe there is a multiplexer connected, which you can use
The display was connected to a single, main board. I looked at it, but honestly, I wouldn't know how to read the pin routes.
My plan B was to just test the pins as well. But I'm the type of tinkerer that tends to set fire to things XD.