The RW6 (Rag-a-Muffin), or Ragwing Sport Parasol, is a wood and fabric airplane that is designed to meet ultralight weight when constructed of clear white pine and when the plans are followed to exactness. Keep in mind that white pine lighter than spruce, and much lighter than douglas fir. Each of the three is slightly stronger at the expense of a slightly more weight.
Here is an example that was listed on Barnstormers.com - not sure who built it, or any of the specifics
RW6 built and flown by Wayne McIntosh
Wayne did such a great job!
Jim Smiley's RW6 with Rotax 503.
John Wiekel built this plane.
I think he just has a small 2 - 1/2 gallon gas jug for the fuel tank. I'm not sure if the plane met the weight for Part 103.
One thing that Ragwings are NOT known for having a nose cowl. John Weikel did a good job making one of his own design that appears to work well.
This photo showed up with a plane listed on barnstormers. Unsure of the builder or specifics of the plane. It looks to be built pretty close to the plans.
This may actually be a "Texas Parasol" - very similar in looks.