The metal cylinder attached to the lens board and connected to the lens shuttle release; what's it's function?

It sounds like you are describing a solenoid. It's purpose in days of old was to synchronize flashbulbs to shutters that had no internal synchronization. Does the cylinder have 2 small holes in the bottom of it with the words "graflex-2" or "graflex-3" above the small holes?
Or perhaps if it is a Heiland solenoid, it will have an "H" imprinted on it with 2 small prongs on the side of it.
A cord was connected to either the holes or the prongs and the other end was connected to the flashgun handle and the shutter was released by pressing a red button on the flashgun.
See if this might help.....

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=008FBx

<font size=-1>[ This Message was edited by: Jack5541 on 2004-06-06 12:02 ]</font>

The solenoid is very useful as a remote shutter release, and was installed on a great many flash-synchronized shutters for this reason. It may be worth getting a three-cell switched flashgun of the "Graflite" variety, which was a kind of precursor of the "power grip."

As to contribute the same answer as the rest of everyone else is, it's a Solenoid.

In basic instruction, its an electromagnet. Lets say you're using the Graflite. The Graflite uses three d cell batteries. Theres a small red button on the top of the flash unit. When you press the red button, it ignites the flashbulb AND sends a current through the sync wire to the solenoid. The polarity in the solenoid thereby reverses, pulling the shutter release about 15-30 milliseconds later. This allows the bulb to be at the height of its power when the shutter opens.

Very primitive indeed, but i've actually found it more reliable that the bipost in a few cases.