Atwater Kent engine ignition

I'm looking for information on the Atwater Kent ignition coils pictured below. I have 3 units total, two are the same model/type, one is simply in better condition than the other and has all the parts.
Atwater Kent made popular ignition systems for early Ford and other automobiles as well as for 2 cylinder boat motors.

One unit has a simple "on/off" switch on the top right, it swings to make contact. On the left is a button marked "start". I've heard that this causes a spark at the plug and if the engine is set right, simply hitting that button and releasing can start the engine.
There are a set of 6 posts, 5 are marked as follows:

and an unmarked post which is obviously the high tension lead post. It has a screw on insulator made of a hard material sort of like bakelite. I believe INT means "interrupter" as in breaker points.

The unit on the bottom left is the same only different - it has a large lever marked "off" and "on". The lever is locked in the off position and appears to require a key to slide it to the on position. I do not have a key and am interested in obtaining one. It also has a start button, apparently for the same reason as the other unit - if the cylinder is charged and up on tdc hitting that button causes a spark which would ignite the charge, turning the engine over.

I am very much interested in obtaining more information such as:
What applications were these units used on?
Wiring diagrams?
Missing switches for the unit shown on the top right.
And of course, a key for the one unit!


Click on a photo for a closer view.


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