The booms are actually elliptical for the most part, they only become square at the wing end for ease of attachment. Although I suspect even that is about to go as you can see in the "Tail Boom Attachment" thread!
I found an old posting of yours and asked a question through it. I am not sure if you would notice it or not, so I'm sending you this message. You found five EAA magazines that showed various illustrations of, for example, the Ramsey Bathtub, on a Russian site. You provided links, but they don't seem to work anymore. Did you happen to download and store those for yourself? If so, would you mind sharing them with me? Thank you, Shawn.
Shawn I have 3 magazines in *.djvu . They are of 10, 11 and 15MB . If your email can recieve such attachments, I can send them to you, each in a separate email. You must install free DJVU viewer to see these files.