I have seen the Rolla-V dies for press brakes before, really want a set and am saving my cash for some. In the mean time I spent some after hours minutes machining and welding a set for myself. Just using a standard V-punch for right now but in the near future I will build a few radiused punches.
These things are pretty trick, if you search YouTUBE you will find a few other videos on how they work. My biggest reason for doing this is to be able to bend with a larger radius with accuracy for brake pedal arms or any other large material