Barry says:

As you can see, I have a little floor edge jig which I use if there's no original (trustworthy) metal to use as a guide for establishing the exact position of the floor edge. If this is out, it can tilt the whole outer sill, leaving you problems ahead when it comes to gapping between door and outer sill.

You can also see that the area beneath the torque tube is all stripped out ready to receive a new torque tube end and surrounding sheet metal.