So when trying to fix the tone ring two pieces just fell off in my hand and I ended up with this.
Oops! But with some adhesive, epoxy metal putty and some little modelling files I managed to get it to this.
Now to my eye it looks bang on. So hopefully it'll hold together ok and be good enough for the sensor. That I won't find out till the wheels are back on. On the plus side my brakes are all finished and back on the car and just need bleeding.