I too have never understood all the fuss about getting the timing exact when moving the spark lever changes it anyway. I initially set mine with the spark a notch or two down from full retard so it gives me the ability to go a little more retarded or a lot more advanced. The question about why so many folks set the timing using a variety of exact methods was asked some time ago but I never got a good answer. Seems like most think the A engine has to be tuned perfectly. Agreed.... listen to the engine while driving and adjust accordingly.
Glen