So we have literally hundreds of surviving Dussacks of all types in museums all over Europe, particularly in Norway, but how were the actually worn?

Did people wear them with plain loop-style scabbards like the Messers in Breughel's pictures? They were rather low-status weapons, after all.
Did they use rapier-style three-point suspension systems? Some of the pieces are rather intricate, after all.

I'd like to make a scabbard for my new Landsknecht Emporium Dorothea, but I don't know what style and what suspension would be appropriate and I've not easily been able to find evidence to base my choice on.

Does anyone know more about this?

We ran into the same issue, so I'm more than eager to see if anyone has a definitive answer. Our go-to idea was looking at saber scabbards, especially Hungarian ones from the border wars period because sabers here were very close conceptually in our opinion (widespread, rather similar blades, and exhibiting the same range of from-poor-to-high-nobles). It's still a bit of a reach though.

That's a shame, I was hoping you might have a more definitive answer.

Their suspension should transfer reasonably well. It can't really be tightly strapped to the body due to the shell and thumbring putting wear on clothes and being generally uncomfortable, a full-blown rapier suspension seems too opulent, at least for a type g dussack-hilt.