Dove into my manual again and found that the switch wasn't even mentioned in the parts/equipment list. It was added manually in this one.
I also found some more proof of the originality of the ARK-LES Heavy Duty switch. A switch, which closely resembles the one you found, was drawn In one of the 3 "Location Of Equipment" drawings. (on the left side of the dome light)
This is enough evidence for me to start looking for them.
Thank you for sharing the info on the switches (And everything else in this thread!)