Edit.

I'm not so sure about that. Looks like the cables in the foreground of the 2nd pic are for an AT power switch.

Those headers do seem weird though. Is this case from one of the major brands? Might be a custom layout for a specific motherboard.

If you can trace all those wires, you should be able to pull them out of the headers they're in and put 2-pin headers in their place. For switches, it doesn't matter which way you connect them, but for the LEDs you'll need to figure out which wire is + and which is ground.

the three pin turbo switch is a latching switch, normal position being , let's say, top & middle pin, pressed position being middle & bottom pin.
attach it to the mainboard two pins in any position that you want. In one position the mainboard will be in turbo with the switch in normal position, in the other the mainboard will be in turbo with the switch in pressed position.

the 5 pin connection is for the power led & keylock switch. It connects to the mainboard in only one way, ie the correct way. looking up the correct way will be best, and i'll try to find it in a minute.
as you can see the keylock switch is red & black and the power led is green & white. edit https://allpinouts.org/pinouts/connectors/mot … at-led-keylock/

1     1 2 3 4 5 
2     . . . . . 
3
45 pin CONNECTOR at the computer
5Pin 	Name 	Description
61 	LED 	LED Power
72 	GND 	Ground
83 	GND 	Ground
94 	KS 	Key Switch
105 	GND 	Ground

ie pin 1 is the green wire.

The turbo led is yellow & white and is only two pins.

Thanks for the info!
@weedeewee:
absolutely correct!! I checked the 5pin header on the board and found the 3 ground pins.
It appears the 2 digit display board is powered by the PSU and the turbo led is connected to this board, not to the mainboard. I‘m going to test it when I get home after work.