We built a dinette in back where the gaucho was and then added ledger boards for a removable upper bunk support. There are pictures
here.
Our upper bunk crosses in front of the window, so the open/close levers don't work when the bunk is in. We only use the bunk when our adult kids join us at Burning Man, where the windows are sealed anyway. Here's a picture of the dinette in its eating configuration. The bunk board rests on top of the ledger behind my husband's head.