What is up with the UCA?

They both are "twisted", just one more than the other apparently. It could be a factory design since the other metal would probably show distortion (as you note). I have 2 off at home, but from a 1964 so different PN. I'll check if they look identical.

The only force during driving that I can imagine could apply a twisting force would be if the front wheel was pushed back hard, say from hitting a curb or dropping in a hole. Even that wouldn't apply much force at the UCA ball joint. Is the direction of twist consistent with that force?