Thanks for this insightful comment. I hadn't known how encodings in filenames are dealt with by CLI utilities.

It looks like some versions/builds of rsync are encoding-aware (e.g., http://blog.gimpe.com/2009/09/13/tip-use-rsync-to-convert-fi...), although some recent builds may not be (http://cygwin.com/ml/cygwin/2011-05/msg00467.html).