Jerome,
I saw David Springette demonstrate making a very similar piece about 10 year ago.
As above David published it in one of his books. We were fortunate to have David at our AAW symposium a short while ago.
It alway fascinates me that people get the same idea from widely different back grounds.
How did you come up with the idea and what technique did you use?
I got the idea to make a Ball in a Ball from A conversation I had with David.
The method David used, which use I the Ball in a Ball, are derived from the bodger chair joint.
One I saw Roy Underhill do on the woodwright show.
Yours is much larger than the 2" ball David used.
Nice job
Al