I wish that I could remember more of the corrective actions for the runaway stab.
When on B707 Major Maintenance at BA I understood the procedure was for the Captain to grab the trim wheel on the F/O's side, the F/O to grab the trim wheel on the Captain's side and the FE to open the circuit breaker for the Stab Trim Motor. The ultimate engineering fix was a mechanical interlock that gagged the stab trim drive system if pressure was applied to the control column in the opposite sense - i.e trim runaway nose down, pilot instinctively pulls back on the column and the drive locks and vice-versa. The ultimate fix for Dutch Roll was a full-time rate-rate yaw damper.