Whilst I found this tree house to be interesting, it seems to be far from practical because there was little to keep the wind and rain out, though I suppose, in the book, that might not be such a problem.
Be that as it may, and if it was relatively waterproof, then the furnishings would probably survive, and one had to also assume that much of the furnishings, such as the writing desk below, would have washed up as debris from the shipwreck.
The stove and oven would have to be built by hand, and it is ‘remarkable’ such well-fitting stones were available. It doesn’t look like it’s been used for a while judging by the amount of gree on it. Perhaps it is not in a waterproof area.
The dining table and the shelf in the background have that rough-hewn look about them
A bit of man-made equipment here for drawing water from the stream
And though not made in the era of electricity, there is an opportunity to use the water wheel to do more than it appears to be doing
And tucked away in a corner the all-important study where one can read, or play a little music on the organ. One could say, for the period, one had all the comforts of home.