They're VO Retro Cages (w/ hook) with "Macchiato" (Honey) colored toe-clip leathers sewn around the outside edges. I was inspired by a post on the VO blog where someone did the same thing.
It was really quite simple. Took me less than an hour to do all three. The cages are tight for regular bottles, but they bend easily enough to make room, and are springy to hold the bottle in place 'cause of their ring design.
-Gene-