Lego!

[kresty]

All of this about the Lego Greebles, but where do they go? The Greebles are recessed in the skirt about 2 bricks + 1 tile. In other words, there's a row of solid brick. Under that is another row where the bricks start staggering. The bottom of the tiles on that row are about flush with the skirt of the Sentry Droid.

(As far as I can tell, there's some error in the photos, but that is close to my memory).

The Lego Greeble Position WRT the Skiert on the Sentry Droid
The Lego is recessed under the skirt. There is a solid row of bricks, and the smooth tiles on the bricks below that row are about flush with the edge of the skirt.

Note that if there isn't enough room, the top row of bricks could either be turned into plates, cut, or perhaps even removed completely.