With regard to the Boscombe Down cct board mod. I have not seen this on any unit before, so this unit must have been their test bed. I did help the guys at Boscombe Downs a few times in their workshop but was not aware they were modifying the units. It looks like its attached to the Qantizer cct bd, which is the large long board next to the platform. It may have been a data collection board. The qantizer board receives the raw acceleration data from the accelerometers and converts it into velocities and distance and then sends that data to the computer boards. The other boards in the gimbal area are: Gyro spin board, Temp control board, frequency control board (2 cct boards - one on top of the other, and the other board is the 26v aux pwr supply.