Hi Stephen,
I started writing a long response then decided to give you a way out. If you set the environment variable SUMA_FLIP_X_COORD to Yes, then SUMA will flip the X coordinate. Note that SUMA will still label the surface as LH, and pressing the '[' will hide the surface, etc. So you'll need to obfuscate the surface's name so that SUMA cannot guess which side it really is.
I am not advocating anyone but you mad men use this ENV. I will not document it in suma -environment's output.
Binaries will be available soon.
cheers,
ziad