Dave Russo's, "Construction of Tubular Steel Fuselage",recomends the construction of the top, and bottom first, then arranged to allow the verticle members to be inserted.
Although he admitsthis method to bemore labor intense, because of the extra jigging. You are rewarded in the end with less frustrations, in trying to achieve symmetry, paralleism, and accuracy of various points.
However, in my review,I have yet to finda "homebuilder"who has constructed an airframe in this manner.
Does anyone have any opinion regarding the order of construction, in this regard?