Gloria, my wife, has a Road Hawk that had some minor electrical problems. I called Roadsmith in Minnesota on advice from the Roadsmith page on this board and talked to Mark - he is the Honda/VW tech up there and helped a lot. Check on the Roadsmith page. They are pretty good as responding to questions.
As far as documentation, not much is available. PM me with your email - I can send you a spec sheet and info on a Road Hawk I downloaded from a Honda dealer in OK (the RH was probably a trade-in) and a sheet from the Trike Shop (now called Roadsmith) on the VW trikes they made.
BTW, is the pic in your avatar an actual picture of your trike? That pic is of a Runabout, not a Roadhawk. Gloria had a '91 Runabout that she loved, (pic below) and now has 2007 Roadhawk (also pic below) that is not as loved. Nothing wrong with it, it's black (which she doesn't like) and it's just not the trike she remembered. The roadhawk has more modern styling, is a bit longer and according to her just feels different. She saw your avatar and said, "That's what I want if it's an automatic." If you would like to upgrade to an actual newer Roadhawk she might be interested in some sort of trade deal.
Gloria's 1991 Runabout
Her current 2007 Road Hawk