Since posting the above, I have spoken to the UK Sinar Guru (about my P3 order), and the "live video adaptor" is the LC (liquid crystal) shutter, and you can only use it for lenses with a front filter thread of 80 to 100 mm, and only tethered to captureshop.
I suppose that your info is correct, I once received that LC shutter from sinar Belgium to test, and I used it on the P2.
However, as I mentioned, I didn't like the workflow.
Why do you use liveview for, composition?
The back only works tethered, no inside buffer or CF-cards.