Forgot to update, built this 6 months ago.
Took about 30 minutes to build:
used a 1″ wood drill,
a hatchet to made the tenons on the legs to 1″,
legs made of juniper to forestall rot,
the clamp lumber was a split hackberry that later cracked, have to redo.
Lessons learned: make sure the front legs of the horse are far forward not to touch the lower foot clamp when fully extended.