Went to the shop today, despite the heat, and did some more work on the center foot's caster wheel, the new center ankle, and the new head.
I trimmed off half an inch from the caster wheel bracket to make all three feet the same height.
The only things I did to the center ankle today was drill the foot mounting hole and trim off excess from the top.
For the version 2 head, I finalized the measurements and cut out the new head rib template. I also made an 18" in diameter by 1/2" thick disk to mount the ribs to.
In comparison to the original head, the new rib looks identical in height plus the crown of the head.
Next time, I'm going to make the next two pieces for the center ankle and use the new head rib template to make eight more. I will then arrange these eight in a circle on the disk I made. I will route grooves in the disk for the ribs to sit in. A half-inch wooden rod will sit in the center of the disk to help align the ribs together. I will also bring the Rockler Bearing to align on the bottom of the disk.