I think the "Pullman" name is the key to finding these things, as we discussed in earlier topics about folding sinks (e.g.
What more could you ask for !, Europeans are way ahead). I think this is a clever and useful idea; I've seen it used in a Class B motorhome.
Another match from a Search for Pullman:
Cool sink on E-bay!, Re-doing your kitchen?
Maybe I'm crazy, but does anyone else find it interesting that the originators of this topic and first one linked above are both named Bonnie (but are different people in different places), have nearly identical trailers of a somehat unusual style (but of different makes), and are both looking into fold-up sinks?