interesting, I just checked a bunch of my cranks and see very small cracks on them. The pre 72's look pretty good and savable with a bit of filing. the 84s look smoothed out in that area and okay, the 77's seem to be the worst (and the shortest at 170mm) and I have yet to check the 1980 180mms.

Edit: These are all record crank sets and all different lengths so I was curious to see deiferences.