This prints with no supports if you print it upside-down and rotated to make the lid edge flat against the print bed - see the Cura screen shot.
Note about rotation in Cura: by default rotation is by 15 degrees. To rotate by 1 degree increments, hold down the shift key when you click to rotate. The model requires rotation by 140 degrees (see the Cura screen shot).
I made the angled lid especially thick so it would adhere to the print bed well. If it were thinner, the print might break loose from the bed during printing, because of the 40 degree angled tube that fits into the nozzle of the Dust Buster.
Most printers I know of can print an overhang at up to 45 degrees off of vertical. This angle of 40 degrees should work fine.
The indentation of the lettering is deeper than I'd like, but Cura seems to ignore features under 0.5mm thick. I used a Sans-Serif font in FreeCAD to avoid small details that Cura would disregard. Note: FreeCAD's True-Type fonts, available for many uses, are in the FreeCAD installation folder.