One of the circular wheels you describe is probably my 3-bearing AOB calculator. If doesn't calculate speed or range. But it could help to verify the correctnes of your drawing up to this point.
The 3 bearing AOB calculator is based on my design:
http://www.subsim.com/radioroom/showthread.php?t=147719
The MaGUI mod should have the explanation how to use it somewhere in the documentation files. But the above link explains it perfectly. (I hope) Align the differences between the specific bearings and read out the AOB at the first bearing. Then add the difference between bearing 1 and bearing 3 to the AOB in the window, to get the AOB at bearing 3.
The shown AOB is correct insofar you adhered to the equal time-interval requirement and not turning during the procedure.