Do all Dura-Ace, EAI, and Campagnolo cogs have the same threading? My understanding is Shimano and Campy lockrings and axle nuts are not compatible, but that their cogs are interchangeable.

I'm looking for a couple more cogs for an old Campy high-flange hub. I plan on picking up DA, EAI, or Campy, depending on what I can find at the LBS.