Sep1 Autopilot
When I was first posted to Lossiemouth in 1972 my job was carrying out 2nd line servicing of the SEP1(MK9) autopilot system this was fitted to the 8 sqdn Shackletons and as i recall it was very similar to the Sep2 (MK10)except the gyro unit was completely enclosed unlike the Sep2s gold fish bowl gyro unit.