If you do your own calculations, please be aware of a very common error. Some manuals use a formula for C/G which uses the distance between the main wheel and the tail wheel. Others use a formula that use the distant to the tail wheel from the datum. Either one will work, but if you use the wrong distance to the tail wheel it creates a 3-5% error in the final C/G. It usually goes unnoticed as it is small, but I have seen this even from official W&B sheets.

Matt H