I finally got the starter off. I'll tell you, that upper bolt was sheer HELL to get off. It's a 3/4 and it was near impossible to get a wrench on it. I had to switch off using a box wrench, an open end, and a small adjustible.
Here is a picture of my starter:

[IMG]http://i7.photobucket.com/albums/y261/bohon/56%20Chevy%20truck/Starter033.jpg[/IMG]

I disassembled the solenoid to see what I could find:

[IMG]http://i7.photobucket.com/albums/y261/bohon/56%20Chevy%20truck/Starter036.jpg[/IMG]

It turns out the plunger had fused to the contact inside the solenoid.Check out the outer edge of the round silver disc and also the contact above my left index finger. You can see where the two melted together:

[IMG]http://i7.photobucket.com/albums/y261/bohon/56%20Chevy%20truck/Starter039.jpg[/IMG]

[IMG]http://i7.photobucket.com/albums/y261/bohon/56%20Chevy%20truck/Starter040.jpg[/IMG]

[IMG]http://i7.photobucket.com/albums/y261/bohon/56%20Chevy%20truck/Starter041.jpg[/IMG]

I checked my brushes and commutator head. They look good to me:

[IMG]http://i7.photobucket.com/albums/y261/bohon/56%20Chevy%20truck/Starter043.jpg[/IMG]

To my surprise, my local NAPA had a replacement solenoid in stock. I made the repair but have not installed the starter yet to try it out:

[IMG]http://i7.photobucket.com/albums/y261/bohon/56%20Chevy%20truck/Starter044.jpg[/IMG]

1956 Chevy 3200