[Squeakland] reflection symmetry

I'm attempting to perform a 2-D reflection symmetry on an object by doing a left-right flip 180 degs - as depicted in the attached jpg (assuming it comes across OK). Basically what I've done is sketched 1/2 of a (bilaterally symmetric) leaf, moved its rotation center to the axis of reflection, and in a script:

Sketch's rotationStyle - flip left right Sketch turn by 180

However, when I execute the script, the object gets flipped "in place", about the center of the object (as if I'd never moved the rotation center), rather than about the rotation center as I desired. In fact, moving the rotation center anywhere has no effect on the flip action.

Suggestions?

--Randy