Researched & built "Hartsell Slide Stick" as dual sticksmod

Hartsell Stick Components

Handles in place in horizontal sleeves (wires are for pulling stick grip electrical wires)

basic Hartsell Stick

Further dual-sticks research.  Found a "Hartsell-Slide-Stick" solution on the 701 builder's website (www.Zenith.Aero).  The solution utilizes the std 701 Y-Yoke, but adds a horizontal bar across the top to which L-shaped "handles" are welded into position where a normal dual-stick would be positioned.  Seems to be the best solution. 

Modified the kit Y-yoke with the horizontal bar welded wit adjustment bolt (AN3).  The L-angle grips have 4  holes drilled ~3/4" apart for adjusting the position of the gip to suit the pilot/co-pilot.
The 6" of the vertical rod of the std Y-yoke was removed and is replace by a 6061T6 tube fitting inside the yoke pieces and is also drilled with several holes  3/4" apart to adjust the height of the sick to suit the pilot/co-pilot.