I believe there are two different types of dual point systems for vehicles.
Bare with me, I've never owned one, but I've seen them worked on.
One type is used on (typically) prewar cars: V-16's, V-12's, and some high-end 8's.
One points set and condenser is used for half the cylinders.
These are tricky and complicated to work on, and need special tools.
You can read about how these systems work if you have a pre-war Dykes Automobile Encyclopedia (the Bible of pre-war vehicles). Bring strong glasses!
The second type is typically from the American muscle car era.
With the two points there is an overlap of point open time (and close time), thereby optimizing spark intensity. The two points sets don't open/close together at the same time,
After-market performance systems for Model A's are probably like the second type, I would guess.
So, remember to bare with me on this. Its been many years since I've seem these systems. In fact, if someone is 'sharp' on how these systems work, I'd love to hear it.
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