Twofold question here:

* It's not easy to tell from the photos, but what is preventing removal of the motherboard without removing the image sensor?

* With some cameras it's possible to mark the positions of the sensor mounting screws, tighten them all the way down to determine their absolute position, then remove them--yielding some sort of confidence in the ability to reinstall them to their original position. Is that feasible here?

Great teardown guide, thanks!