The key to a proper set of vise jaws is the proper material and heat treating. Although I am sure you could get a set of jaws made at a voc/tech high school that would fit, I doubt they would be satisfactory. In short, the only way I see to properly repair this vise would be for a competent machine shop with an engineer with a metalurgical background to identify the material used, and apply the proper heat treating. As someone else pointed out, this would likely be more costly than a new vise. Unfortunately, the vise in question is no longer made, so unless a used one can be found, it looks like a different make is in order.