As it turns out the PCB used in these switches is common to Mondeo, Focus, Fiesta and Transit vans. And in a Transit van the switch activates Tell Tales for the Front and Rear foglight activation (if fitted to the vehicle).
The LEDs can be added (Green and Amber/Red) for front and rear respectively, but still don’t light until a pair of current limiting resistors are added to vacant pads (560R surface mount would do the trick) and bus bars added to connect to the switch.
The two LEDS are the center bottom (Rear) and bottom right (Green). The left two Bus bars on the upper right are added. Obviously one for front and one for the rear. On the reverse side it’s pretty easy to trace the tracks to see the pads where the resistors need to be added.
(And yes, I’ve also converted all the other LEDs to blue).