One of the posts on the SCAL forum started me playing with circles in Inkscape and I created these nesting medallions. Let me know if you would like more variations.
The download includes a layered svg file for use with SCAL2 and five single layer svg files. These files are for personal use only. Feel free to link to this post, but the files are not to be shared or distributed in any way.
Download the files from here.