country calls, the original Vulcan B1 had a pronounced nose-down trim change when the bomb doors were opened. So the test team and designers came up with a mechanical design to interlink the bomb doors with the elevator circuit so that the autopilot could hold the aircraft leve throughout the bomb run.
This was found to be unnecessary on aircraft with the ECM tailcone fairing, so was removed on the B1A and B2.
Another Heath Robinson compensating device was the ‘datum shift’ in the Gnat longitudinal control system which compensated for the landing gear extension forward CG movement through a piece of bike chain connected to the Hobson tailplane motor input. That gave another 3-ish degrees of TPI with the gear down. Simple, but effective!