Improving cornice on Wall Unit...

Hi all,

I have a single wall unit that sits above the island area of a U shaped kitchen. I cut and mitred the cornice and then discovered that the ceiling slopes by about 5mm as it passes across the unit. Now the unit has been up for some time, is level (got lazy in doing the finishing touches!) and is tiled underneath so lowering the unit isn't an option.

I elected to sand down the top of the cornice in one corner so that it would fit on top of the unit, but it looks odd due to the...

Improving cornice on Wall Unit...