RCMoeur 

Thanks for the info. My reaction was based on my past experience of a seemingly near 100% correlation of silver Nuovo Record rear derailleur with 753 chainrings and black Super Record derailleur with the cutaway 753/A chainrings (which it seems became the de facto standard design for most vendors by 1980). I'm a civil engineer by training, not a mechanical engineer, and I'm wondering how much did that inner circle on the 753 contribute to strength or lateral stiffness.

Then again, my racer has a crank made from an old Super Maxy which had a fixed swaged-on 52 tooth chainring that I sawed off just above the 110 bolt circle and then bolted a chainring on each side - not exactly a recipe for stiffness itself.