The crankarms are correct, it is only the chainring that is not. The correct chainrings are as pictured, though these appear to be chrome plated, as opposed to the correct nickel plating that would have been used in 1932.
Regarding the frame size, I notice that Robbins competed in three events at the 1932 Olympics, one being the individual road race. It was not unknown for riders to use a larger frame size for road events and though it was fairly rare at the time, I'm wondering if he may have used two different bicycles? Depending on his preferred rear brake, that might explain the orientation of what appears to be a drilled hole in the seat stay bridge.