I actually noticed all those paintings from your DREAM mod when I installed Decorator and hung one of them above the bed in my ship.
When I realized the mod only lets you place a few paintings, I figured out that those textures aren't the same as the paintings you get in the palaces and banks. What you retextured was the 3D paintings used in world space, while my textures go to the inventory items you can click Info to see.
My hope is that the Decorator mod sees some improvements, one of which might be the ability to add custom items to the store. At that point, I'd like to add all the base inventory paintings in the game as 3D objects that can be placed in the game world. They could also be used as a modder's resource to be added elsewhere, but my aim would be to place them inside player homes / ships for flavor. By upgrading the textures, it will make it worthwhile to actually place them in large sizes around the home.
Having collected all the paintings (as best I could, not realizing some paintings are duplicated) back in the day, I decided to try collecting them all again. That led to my Numbered textures (and a spreadsheet that's far more complicated than it needs to be).
I'm also working on re-texturing the message box. The edges are fine, but somewhere in trying to blend the center texture, I got a bunch of weird patterns that look funny. I tried blurring that part of the texture, which isn't too bad in game when you're focused on the text, but it still isn't good. Not that the message box only affects the paintings, but it makes it more obvious when the image is high resolution and the message box is not.
Also, I'm having problems in 0.10.26 that the message box doesn't resize itself to fit the images at all any more (even with no mods activated). I was hoping there would be a way to specify a render height for the images to fix the couple that were broken in vanilla, but I'm not having much luck finding it in the DFU documentation, if it exists. And since they're all broken now, I really don't know where to begin.