Planet Sinclair: The Black Watch
The casing was impossible to keep in one piece. It was made from a plastic which turned out to be unglueable, so the parts were designed to clip together. The clips didn't work either and the problem was turned over to a subcontractor. Sinclair later (much later) received a small box on which was written, "We've solved the problem of the Black Watch!". Inside was a Black Watch with a half-inch bolt driven though it.