I 've finally finished the coversion from underseat steering to the "Windcheetah" style overseat steering. The change was necesitated by my plan to put a floor and wheel wells into the fairing. The old handlebars would have hit the wheel wells every time I tried to turn. As you can see from the pictures I've bolted it all together just like the rest of the trike. I used 1.25" square tubing and a piece of tubing that's the same 7/8'' as handlebars. 
The snow had melted off the road soI took it out for a test ride this afternoon. I didn't take it down a hill but I suspect I need to tighted the connection with the universal joint. There's some play in it. The other issue is that its prety hard to turn. The steering assembly is attached to the frame with a bolt that goes through a bushing on each side of the frame. Maybe some oil would help. The only other problem was that my rear derailer cable cought on the bit of bolt I didn't saw off fush with the nut.The other advantage of this set up is that I had a chance to redo the steering linkage and hopefully improved the ackerman compensation. The old set up was off and an I went through tires about every 1000 miles. The turning radius dramticly improved. The old handle bars used to hit the seat limiting the turning circle to the width of my little street.
