Hi Prof,
If the prisms are aligned 100% cirrectly, then CA will be symmetrical. Like you, right now, I seem to have more on the right hand side than the left, but I know that I need to remove that lid yet again. I have the image prefectly framed right now, so not game to alter the prisms just in case I mess up what I have.
Slightly off topic, but thought I would share (actually tease). I have have prototype plastic case for my lens (MKIII) and have been experimenting with a cylindrical correction element, that, for these initial tests anyway, seem to almost completely remove CA.
Clearly there is way more testing to do, but so far this is looking promising.
You can see a photo of the prototype
HERE...
Mark