Annu,
I don't know what a c31 is but you might try straightening it.? Some materials like hot rolled steel keep a memory of their original shape.? Heat, quench and some persuasion can relieve the stress from the new twist and return to its original shape.? A mapp gas torch might be enough or a friend with an oxy-acetylene rig. You would not be out much but time if it doesn't work.?
Jonathan Smith