I am only guessing at the weight. I have read that these can be weighed by weighing each wheel separately and adding the values together to get the total. Have you ever tried this? The article also suggested to put blocks under the two wheels that are not being weighed to keep the plane level, then move the blocks around as you weigh the other two wheels, until all three are weighed with the plane more or less level. I will try that tomorrow and see what kind of number I come up with.