Looks very much like the Gian Robert cranks, and I would be making sure they had no cracks. Mine do, and two out of the three currently on that auction site have them. The crack is somewhere between the inner end of the elongated hole in a crankarm and the square hole in the centre. I think they were cast/formed while hot and in shrinkage developed the stress that causes the cracks.

A lot of left arms and rings listed, precious few rights.