In our new MBA, we will have two matching sinks in the main part of the bathroom. The watercloset, for lack of a better term, will also have a small sink (partly because the plumbing for it is already there, so why not.)

Anyway, the space is a tad narrow and the home is vintage, so I was looking at old folding railroad sinks. (photo below) I would not need to fold it away, but you have to, because that is how it drains.

Has anyone ever installed such a thing? I am wondering what a plumber would say, and what the visible plumbing will look like.