Randy,
That looks good. Unfortunately, since this moves the bucket down and back slightly in relation to the dipper, the changed geometry may not mate well with either the Kubota mechanical thumb or for for those of us who have added hydraulics to that thumb. The end of the thumb would hit higher on the bucket, instead of at the bucket teeth - should still work fine for picking up rocks, but maybe not so good for plucking out sagebrush and other deep tap rooted large plants - course, one could modify the thumb to fit better?