The frame is a bit weird. Square door in a curved opening.
Our 19 had one edge along the
fridge wall and the opposite vertical edge supported by a curved piece that I called the surf board. It’s more like a half board. A header board across the top connected the the two usages and had the slide in it.
It’s been a few years since we redid ours. If you can find one to look at in person it makes sense, but it’d be hard to do from scratch.