Here is a bench vise that I acquired awhile ago. No name is visible anywhere.

 

The  "U"  ( slide/guide)  is 1-1/2" round stock and 3-5/8" on center.

 

The jaws are 5-1/2" wide - corners are in bad shape

 

When full open the gap between the jaws is 7-1/2"

 

This vise works very smoothly during the opening and closing and is very stout.

Very Cool, Ive never seen one like it.

Any idea what it weighs?

Have plans to put it to work?

While looking for something else, I think I found the maker of your vise.  The front jaw is a different shape, but there's enough in common that it's probably from the same company.   It was made under contract for the Ware Twin Engine Truck Company of Minneapolis.  The hard part was figuring out what forum I had seen your vise on.  

 

Here's a couple links with info:

http://tinyurl.com/km2nqc3

http://tinyurl.com/mgs4kqo

http://tinyurl.com/lby23fn

 

 

Never heard of such a critter.  Definitely something neat to have, and I wouldn't mind having one of my own!