Here are a few more bits of information on this fly which resulted from questions on another forum. I thought you guys might like to have it.

The beads appear to be 3 millimeter for the larger head size and 2 millimeter for the smaller body size. On smaller hooks I would ordinarily just use the 2 mm beads. They should be available from most craft stores. Another thing you can do with these is use two larger beads, one in front of the hackle and one behind, following up with the smaller beads. This keeps the hackle spread out slightly more than with just a single large bead at the hook eye. It's a small difference with rabbit fur, but another possible variation. You could also use other furs or feathers for the hackle, I just like the "in the water" action of rabbit. Particularly in slower water. If you retrieve it like a streamer you now have a tiny bait fish imitation. Very versatile. I do recommend staying with the Antron for the dubbing as it has definite benefits hard to replicate with anything else.