The V5 states "Approximate first year of use", I don't think it's actually on the VIN plate but the wings do have date stamped on them (If they are original that is)

Easiest thing to do is to ground the wire you remove off the switch, if the light works (With ignition on, obviously) then it means the switch is at fault, if nothing, check for power at the wire, if nothing, then the bulb has most likely blown.

These also have a seperate light for low brake fluid, whereas normally on other cars you have one dual/tri purpose bulb.

Martin