Mysterious Mercury Dash Lights?

[rattlesnakehoey]

What are the factory installed two red jewels (20-30mph & 70-80mph) on my Canadian 1948 Mercury 114x dash gauge. I am reassembling the dash after a long spell and have forgotten?
The two green jewels are turn signals.
Separate gauge cluster (not pictured) comprises amps, temp, fuel & oil pressure.
High beam is at the bottom of the gauge (in between 0-100mph).