Sorry for being slow on the upbeat here... but this is the reply I got from Ivy:
"The tool was designed for bending the steel bones that could be placed at the back of a corset. Most bones are quite flexible, however, for wearers with back problems, heavier steel bones could be used at the back of the corset. These were manufactured straight and then bent by the fitter using this tool to follow the curve of the wearer's spine.
http://www.corsetiere.net/Spirella/Modart_J_G49.jpgThis link shows such bones half removed from the back of a corset. It took the leverage of the 'pliers' to bend these bones. Camp was one such company of many that made back support corsets."
So, now you know, and can get your corset bones bent....or hang it on a display rack.