Docking CV to Base/CV

I was messing around with my CV and the space station I took over when I realized I cannot dock them together. I ended up making a big platform with a gravity generator to plop the CV onto, but was thinking it would be neat if we could place an "airlock" block on the CV and on the base, that would allow a docking connection. It would be great for a couple of CV's meeting in space to trade or whatever, and for docking the CV onto a space station.

On a similar note, it would be interesting to...

Docking CV to Base/CV