ooh, crikey, a can of worms!
Ignoring prototypes and specials, the production ones were I think as follows:
Cam twist- holey, notscooped out back. Early ones threaded all the way down, later ones stainless, threaded at the ends.
Ti stix, were as above, holey, but the back scooped out of the lever, tirods.
' for the road, were ak per ti six, but all the holes kind of joined up into a long tapering slot.
Twisters, flat flipover lever, no cam, as suspension came along and fat legs got in the way of the cam twist design, necissitating a flip on the lever, unless you're careful. It was mistake proofing in a law-suit world. Incidentally, even the cam twist designs shouldn't be fastened like an oe shimano skewer or you'll break the handle, they must be used more like a wingnut.
And then there were the ti-rods I think. No handle, just a bolt through, caphead fitting, so like a security skewer kind of thing.
Then Sun took over. . .
And they fid thefle flickers or whatever they were, looked like a twister but with a cam, and they did cay on with the twister design too, but I'm not sure for how long. I lost touch at that point. And I gues when production went east and a lot of the CNC bits became forgings, a lot of people her lost interest too. . . but it'd be interesting if anyone here can carry on with the story into the Sun era. . ?