thorens double claw lighter with external windshield

I have an old Thorens double claw lighter that after many years of reliable use has broken the spring that holds the flint in place and flicks the lid open to light the wick, i am trying to obtain a replacement spring so i can carry on using this much loved lighter of mine, if someone can supply or steer me in the right direction to get this part i will be a very happy man

Kind Regards Ed.