I'm researching and educating myself in preparation for a build. I've a couple questions regarding welding the fuselage (most likely a LE XL). It seems most assemble and tack the entire fuselage then finish weld. This helps keep everything straight and in place? Would it make sense to assemble and weld as you go, so there are fewer parts in the way? When welding a cluster, would one weld the main parts (horizontal and vertical) before installing and welding diaganol pieces? Or, would you tack everything and weld the whole cluster at once? A search led me to a photograph of holes drilled to allow the tubing to be filled with oil, then drained, after welding, for rust-proofing. Do most do this? How many fill / drain points?