quite rare but they do come up now and again, there are 2 generations of them, 1st gen had a single indent along the arm like on a set of redline 401s, 2nd gen had 2 shorter indents, still looked like a set of 401s but with a little space inbetween indents. they had 4 spline axles and i have seen the different spline configurations on the arms. this would mean if you mixed up a set of arms the cranks wouldnt be parallel, they would be at 90 degrees to each other.
