funola,

This is excellent research and deployment of original thought!

Makes me wonder if this could develop into a retrofit kit to resolve most W123 inoperative tach issues originating from the infamous tach amplifier that suffers the mysterious kiss of death so common to the breed...

Although I have read a few posts about some who have revived their tach amps
with some careful cleaning and reflow of solder joints...but that's another topic.

Anyway, great idea and an excellent post.

Thank you, funola!