Added a few more things.

I've forked the repo and pushed/committed the changes. Modified the CAD Interactive Control, slightly and added another control spec.
Oh dear, I think you have some tabs mixed in with the 4-space indentation in here. I think Python 2 will still incidentally run this, but Python 3 refuses to run scripts with mixed tabs and spaces. Could you convert the tabs to 4 spaces please? Thanks!