My favourite and the most versatile I have ever used was when I was a kid and consisted of a six inch piece of thin cane (a little thicker than a cocktail stick) as the spine with a sliding rugby-ball shaped piece of cork body. Shot capacity about 3BB.
You didn't need any float rings, as you would just thread the line down through the cork body, then stick the spine back up through the hole, trapping the line, and then thread it down through the bottom ring on the bottom of the spine.
The real beauty of this little beauty, for those of you who are following me so far, is that you could vary the position of the body to wherever you liked on the cane, so as to give a whole range of float shapes / body styles / mechanics.
Slide it up top it looked and worked like a classic Avon. Down a wee bit and you had a Chubber. Down even further to near the bottom and you had a ducker, onion, bodied waggler or whatever you want to call that shape these days (still got an original hand written set of Billy Lane Duckers btw.... what they worth ?). Take the body off entirely and use with a float rubber and you had the lightest of cane margin floats as good as a porky quill any day.
I must have gone through hundreds of those floats as a kid, one after the other whenever the cork on the previous specimen split, broke up or wore so that it no longer gripped the cane sufficiently tightly. That was the one slight design defect - not v high quality cork.
I did recently try to whittle a replica but with no joy. Easy enough to replicate the central cane, but how do you shape cork ? impossible to cut cleanly with a hand knife and hopeless to sand..... is there some trick to cork shaping someone could let me in on please ?