Ouch...that's been seriously neglected for a long time. I can't tell if it's a C0 or a C1 from the pics, but it's definitely a C-series vise. The spindle is the worst I've seen, and I've seen some bad ones! That isn't a terribly hard job to build back with weld and then turn a new groove, but that would also mean cutting the handle off, which would have to be replaced or welded back together.
In theory the dynamic could be carefully built up by someone who really knows what they're doing TIG welding ductile iron, then machined back to specs, but it would probably cost more than the vise is worth if you're paying normal welding/machining rates, especially after you stack that on top of the spindle repair.
I think I have a dynamic and matching spindle/handle assembly from a C1 in my parts stash, but I'd have to check. The problem with a new dynamic is that there's no guarantee the jaws will line up properly. Wilton machined the sides of the jaw supports and the jaws as an assembled unit to make them perfect and this was long before CNC made things repeatable. There's a really good chance a different dynamic would be canted slightly right or left. A machinist can fix that by making an offset key for the dynamic, but again we're talking an expensive proposition.
