Control Arms
I have seen both, but do not know what the pattern is, or if there even was one.
Maybe it was a diifference in years, maybe it was a 2nd manufacurer, ?? who knows.
The round style, on the right, that was on my 72, does not look like it has enough meat around the hole to a cut a 1/4 longer slot, for additional caster.
The one with the square section around the bolt hole, on the left, has more meat to it, and looks like it would be safe to do that.
Actually the shape of the one on the left looks very much like the shape of the Moog one.
This clip is from a Global West video.

















