I really like the Win-10 wallpapers they have, but I can't seem to find a way to get them back with DisplayFusion. Any ideas?

There are two ways to do that:

1) Navigate to C:\Windows\Web in that folder there are numerous folders all with images in, copy them to a better location or where you keep your desktop walls.

2) Open DisplayFusion and click on Load Image, then navigate to the above address and choose the image you want.