It seems like Allan seems to know his U.S. Missile Guidance hardware today. It is the Inertial Guidance unit from a Peackeeper Missile. This particular example is in the Hill AFB museum in Ogden Utah. What the sign doesn't say, is that the ball is surrounded and suspended in a liquid, so that it can rotate in any direction without friction.
Allan, over to you!
Beautiful item, that must cost a fortune to produce!
Thanks for posting the photos.
Dave.