I didn't see anything broken off... can you highlight what you are talking about?
The entire support ledge for the rear jaw is broken off. Both the front and back should look the same with just a little bit of the jaw insert unsupported. You can see that clearly on the front jaw. Somebody beat on something that was held in the vise, and the rear ledge broke off entirely. Now the only thing holding the rear jaw in place is two little socket cap screws rather than a ledge the full width of the jaw. When this happens, the vise is worth a fraction of what it would normally be, and is only suitable for light duty. Any significant loading will transfer to the cap screws holding the jaw in place and the threads will strip, or the holes will break.
Often it will start out with just a crack in that area, so it's a place you absolutely have to check when evaluating a used vise (any brand really). That's why vise guys often won't buy a vise that's had this kind of amateur paint job...it's easy to fill in cracks with body filler.
In fact, a Wilton bullet shouldn't' have paint on the sides of the jaws, or the jaw supports. The jaws were made oversized for both width and height. They would install the jaws and then mount the vise on a machine that ground the tops of the jaws even, and the sides of the jaws flush with the body. That way all of those surfaces would be even, square, parallel, etc. On a clean example you can see the grinding marks trace across the body of the vise right across the sides of the jaws. That's also a telltale when guys flip the jaws to put the clean side up and hide the dinged up original tops...the grinding lines don't match. What they don't know is factory Wilton jaws actually had a top and bottom, and when you flip them like that the jaw won't touch the jaw support ledge (because the top, which is now the bottom, was ground in place when originally made so it's shorter). Then you've got the jaw floating above the jaw support, hanging on those two little socket cap screws and after a few hammer hits (a bad idea regardless) the bolt holes fail....victim of another amateur vise "restoration" from guys who simply want to make a buck but don't know what they're doing. <end of rant>