Ha ! That's funny !
I worked for a Dodge dealer in the 70, and never saw them use one....
Probably sitting in the tool room unopened like a lot of other specialty tools.
Ya it's from the 80's they had a meter with a probe that slid in the hole and you could read the timing on the meter instead of using a light, it was a failed attempt at making a new tool that every mechanic had to buy.
to bad for the guys that did.