I do know a bit about the construction of this Litton P-1000 4 gimbal platform. It has two G-1200 non fluid floated tuned rotor ball bearing gyroscopes each capable of measuring two axis of rotation. The rotor uses a heavy tungsten wheel with precision machined mechanical flexures similar to the Kearfott "Gyroflex" dry rotor gyro. The three A-1000 accelerometers are non fluid floated hinge restrained force rebalanced. They use speaker type coils and permanent magnets for servo restraint. Both inertial instruments use Invar as their main structural material for high thermal stability.
Similar Litton P-1000 platforms have been used on the early U.S. Air Force F-15 fighter aircraft, the A-10 Warthog attack aircraft, some of the early versions of the U.S. Air Force air launched AGM-86 ALCM and U.S. Navy AGM/BGM/RGM-109 Tomahawk cruise missiles.