My adventures in getting my Speed Graphic continues, but I think I see light at the end of the tunnel. The nut on the bottom of the front standard that connects the the lever assembly, which locks the standard in place is missing. I looked at a service manual and the description is Nut - Machine (Special). Does anyone know the specs of this nut so I can track a replacement down? Without it the standard doesn't lock into place for long. I'm hoping to avoid cannablizing a replacement standard for a single nut. Thanks again!

The threads are an SAE standard. I don't remember if its 1/4, 5/16 or 3/8.
Measure the outside diameter of the threads with a caliper. 1/4- .21 to .25, 5/16-.27 to .31, 3/8- .32 to .37 inch.
I made one for a Super graphic by cutting a standard nut down with a Dremel and cutoff wheel.

What makes it "special" is that is thinner than a jam nut.

You are a wealth of knowledge, thanks for all your help and taking the time to respond. I really appreciate it!