This might be a new topic for this forum.
What is correct for 1938? Any opinions? (quickly attaching flame arrestor to my computer modem)
Here is what was on a Mark V Z engine I bought in 1980 from Ed Rahal.
They look like the pix in the Mark V manual.
Here is what was and still is on my Mark V T engine.
Here is what Rhode Island Wiring offers.
This one has a bunch more on page 3.
http://www.restorationstuff.com/pdf/RestorationSupplyCompany.pdf
BTW no need to tell me about uninsulated terminals and high voltage; a good portion of my career was working with HV devices.