For the first few months of 1913 Ford used a unique KW coil that fit a wooden coilbox. This was the first KW Williams designed coil used by Ford and is different from all others before and after. Here is a photo.
Notice the wood case is larger and the terminals are in a different location than the later KW design that was used in all subsequent Model T production.
Because they were used for such a short time these coils are very hard to find. Normally I would not go to the trouble, but if you find one of these coils with a bad secondary winding it is worth the time and effort to replace the entire innards to save it.
Here is a photo of one I repaired this weekend for a friend.
This photo was taken after the original parts had been removed from the box, replacement parts had been installed and a small amount of tar had been added to hold the new parts in place. It was then filled with tar as usual.
These coils are very fragile and require great care when working on them because of the thin wood used for the box. If you find one save it, because it can be repaired.
Ron the Coilman
Thanks as always Ron for your informational postings. We owe a lot to you for your continual postings and updates. Your seemingly endless patience in answering the same questions over and over thru the years has paid off many times in the Model T fraternity I'm sure.
Garnet