I've always wondered about that statement in Sheldon's site. I think the "older" must be 60's or earlier.

I have an Avocet triple that was on my 76-77 PX-10 that I'd set up as a half-step & a granny. It was on a mid-70s Stronglight BB. For a short while I put it on my Hetchins, but I decided that I just liked the Stronglight 93 on that bike better than the Avocet. But I ran the Avocet on a standard mid-70s loose ball & cup Campy NR BB. I tried it on a Phil Woods BB from the period when they only made one spindle, and it fit just right. SO, my conclusion is that Sheldon just happen to be imprecise (maybe not wrong, just the dating thing) on this matter.

The Avocet design is actually among the strongest of the period crank arms. Good looking to boot.

All that said, and I'd never seen an Ofmega crank like the one shown by the OP.

Thanks.

and Good Luck.