I will see if I can post a picture of the vice. I bought it new about 10 years ago in an Odd Lot's store. When I took it off the shelf and looked in the box, I knew it was a high quality vice. It does have an area to hold a pipe, and it does not have a lever for opening the jaws, all you do is turn the handle as you are going to open it, and pull, it , it then will slide open.
As I said, it only works correctly if i hold it upside down. Since the parts can only fit in one way, i think the one part i have left is the key, i just don't know where it goes.
The part it made of spring steel, and it looks like it can fit over the screw. I just don't see how it fixes this problem.
The vice can swivel, but it does not have hand nuts, it takes wrench to loosen the vice to turn it.
I thought I could find a blow-up drawing of the assembly of this vice, or another that works in a similar way.