i'm tryng to do with inkscape this:

a simple spiro line with 3/4 duplicate which are scaled without loosing it's parent curves
i've tried with bezier tool, calligraphy with hatching, cloning object, etc.. but i can't get a good stuff if i duplicate and scale i lost original curves
any ideas? i'm using inkscape svn-dev version with new spiro features
p.s. original wallpaper image HERE