Just purchased and refreshed this really nice Quickwerks vice. It has all its original hardware and the jaws measure 5 3/4". It curiously has a much deeper throat from the screw to the jaws than most vises (about 6 1/2", my other vises this size are 4") and I'm wondering if this is common for this style vise? 

don't know if it's common, but it would be handy.

Some vises ran tall, supposedly for specialized tasks according to the old advertising.  But forget the vise, show us pics of the Nazel? in the background!

From a 1907 Columbian Hwd. Catalog, Horseshoers solid box vise can be used for blacksmithing and horseshoing. The flat front jaw is a helpful feature for Horseshoers. The flat is at right angles to the bearing surface and is used for Turning both calks at one heat. The extra width of the jaws and extra depth from top of jaws to top of box allows the vise to hold any size shoe securely. The Horseshoers vise has a greater working capacity than a blacksmiths vise of the same weight; for instance a 60lb Horseshoers  vise opens 6 inches a  60lb blacksmiths vise 5 inches.  The picture in the catalog looks just like yours. Hope this helps!

Thanks for posting Gray Iron!