Steering Column Ignition Switch Bulb
 

Anyone know what type of bulb was used to illuminate the ignition switch in cars equipped with this feature? I thought it was a type 37, but that doesn't fit.

This thread from way back is the closest I've come to the answer: https://www.rx7club.com/2nd-generati...t-fcs5-389231/

From the Mazda FSM 3.4W (SAE Trade No. 158)

https://www.bulbs.com/product/158