Most blokes just make them out of 25 thou.
They are two piece tear drop shaped and have a piece of piano hinge running down the trailing edge . The top section has a hose clamp securing it to the leg at the top closest to the fuse and the overlap of about 1 1/2 inches in the midle keeps the bottom one secure (as well as its termination in the bottom (wheel) fairings. The slip joint stops them from crumpling as the legs flex. Just make a mock up with cartidge paper then cut them out. Take about 2 hours to make them.
http://rv-4builder.blogspot.com/2010/03/fairings.html
Only just shows the very top of one fairing.
I can easily take some more detailed photos of them when I get back home next week.
HTH
Mark Bolton
http://rv-4builder.blogspot.com