I suppose it depends how "micro" we go into it. The minute the original structure is altered in any meaningful way, then it instantly becomes different.

It is the same object " a house", but with a different structure. I think viewing the thing as an overall "object" demeans the fundamental problem a philosopher will be trying to address.

I think if I address the "new boat" puzzle in your op, then I'd view it as this:

If you break down the original boat, whilst replacing the parts with new parts, then build the first boat again with the original parts, then you have 2 different boats, but one uses the original parts. Part of that original boat will be things like brackets and nails, that would be non-transferable. However, if you look at it superficially - it's the exact same boat. But being the pedant that I am, it's completely different.

I really like your posts, I often find myself disagreeing with you, but you put your points across in a way that makes me want to continue the discussion, and requires me to think about how I formulate a response.