I have been filing the divots for couple years now. The pads would not retract after couple hours of driving and then things really started heating up. Recently I came across all the threads on the Forum and the internet on welding the divots. Replacing the knuckles seemed a poor way to go.
Did much reading on cast iron welding so I would have a better understanding of what was needed. I have a wire flux welder but not a super expert with it. If you are welding cast, it should be heated. But cast can be welded if done in small short sections without heating. Filling the divots is hardly large scale welding where temperature differentials don't seem to be a problem. On principal, I did heat the metal first with a torch where it does get out the moisture also (200-400F).
I had been filing and grinding these slides for some time now so my challenge was more than just filling the holes. I had to build some of the areas up to reconstruct the slide back to original size and flatness.
One weekend I worked on one side and another weekend I worked on another side. I spent about 4 hours on each side getting it best as I could. Not sure if I am done yet as I like things to be done properly. How good is good does it have to be.
Since then I have driven the car 2 times for about 2 hours each time running around with errands. So far things have been working well as no wheels have been locking up as before. I 'm still in a wait and see mode as more driving time is needed before I feel like it's really fixed. But so far things look good and I appreciate all the threads and information that others have written up including YouTube information.