TommyW:
Didn't realize that in your original post you used 3 sets of scales!!! If you by a good digital scale (or buy your wife a nice kitchen scale for her birthday!) you only need 1 scale. Then use wooden blocks of the same height as the scale under the other two wheels to keep the model level. As in the previous post, the key measurements are the weight in the nosewheel and the total weight of the plane.
You now need to put your two "spare" sets of scales up for sale. Still a very useful thread for those who have trouble holding 15lbs on one fingertip.