You must recall the Merc-O-Tronic Ignition Analyzer, Mike?
In 1972, when I started professionally repairing chainsaws at an I-H farm equipment dealership in Syracuse, a Model 88 Merc-O-Tronic sat on a shelf, at eye level over the workbench. Totally unfamiliar instrument to me, though.
With a little training from an old timer, and ignition service data from McCulloch and Homelite, it became a valuable tool.
I used that machine every time I performed any breaker points magneto ignition repair, for 7 years.
( Electronic, Solid State or whatever else you may call it, ignition was not in the picture in those years.)
Anyway.... in 1979, I went to work for a TORO Company Distributor and requested a Merc-O-Tronic Ignition Analyzer for the McCulloch products they also distributed. I believe it was the Model 98 at that point. Along with the base unit, it came with 2 different adaptors for Electronic, Solid State or whatever you may call it, ignition.
In my new role as a McCulloch selling/servicing dealer support contact, I rarely ever used it. Never, ever, used either one of those 2 adaptors.
After reading this excellent Wing tips #4 article, I reckon those 2 Merc-O-Tronic adaptors were peak voltage testing devices.
Although I'll most likely never utilize one of the peak voltage adaptors you have detailed the purpose of, perhaps I'll get one off Amazon to add to my toolbox, too.
Thank you, Mike!