I replaced all the ball bearings which is why I took the arms off and open up the BB. The BB is in very good shape (spindle and both cups show little wear). So that's useful; I'll give it a try to see if I can determine whether the play is in the arms or the BB. I've never seen a crank on this tight before (it took a lot of elbow grease to get them off) and I didn't know if the play (which I normally associate with an incorrectly adjusted bottom bracket) could be in the arms.