First, a set of pictures detailing the building of a wooden Vespa has come to my attention.
For the full set, go here.
Second, I want to make the comment that modern innovations tend to develop over a long time frame. Eric Buell's fuel-in-frame designs are wonderful. I love his designs. But, they are not as innovative as might be thought. In 1910, Pierce was manufacturing motorcycles with the fuel and oil contained within the frame.
Lastly, in case any readers are interested, go over to Hack-a-day for some info on making carbon fiber parts.