Originally Posted by MarkofSeaLife
I must be getting far too cynical.
I think so. I looked at some pictures on a Wooden Boat site and they support the sensible notion of moving the old engine somewhere inside the boat (explaining the removal of the heads to lighten it), doing the extensive engine bed work shown, and then taking the old out and putting the new in on the same day. There was probably quite a bit of work involved in opening up enough of the deck structure to move the engines in and out and no point in having the boat open for a long as the structural work took. There was a lot of other stuff done at the same time according to the pictures which show a new mast step so plenty of room to move the old engine.
BTW the structure in all the pictures looks remarkably clean and well cared for.