I have tested an artificial horizon system made out of fish-eye ball compass. 

My compass is blue on the bottom and brown on top. The reason it is blue on the bottom is because I wanted to invert the image with the camera so that it behaves like real artificial horizon. When nose is pitched up - there is more blue on the image.

To make the compass I cut in half two eye-ball compasses so that at least one hemisphere on each was the right size after cut. Then I painted one floating compass in blue and brown and glued them together with superglue. Drilled the hole and filled it with the original oil.