Actually I have an old video of that set up
It shows the little shelf at the back. Note to Ria if you watch this - it was made before my first major moth outbreak! Hence I was mentioning 48 hours in the freezer (rather than a week) and didn't know about freezing food then. Although it's the Savic Mickey 2XL, it's exactly the same cage but with smaller bar spacing. The little lava ledge shelf just filled the gap between the house and the edge of the cage and he loved sitting under it.