I have done the relay upgrade (relays at the fuse box in the existing relay slots with no work done at the dash end) and all is working fine until I started thinking did I have a tell tale light in the headlamp switch on the dash? I have never noted if I did or didn't have one. So I had a look to see if there was one physically there, nothing, it looks like one could be fitted but I have no idea to what type or where the contacts are made (see picture).
I have looked at a later loom I have, this has the same switch but a different plug on the loom with a bayonet type bulb and carrier.

Should there be a light in the back of the switch?? If so what type?? I have an early bullet fuse type fuse board, 1982 A/C van.
Thanks