The DC8 flight controls were all connected to the cockpit by mechanical cables as was just about everything else including a few items that might surprise those not familiar with the DC8. Douglas loved cables; in the gyro compartment just fwd of the front spar it looked like you were inside a harp there were so many cables.
Regarding hydraulic systems-
The utility system (2 engine driven pumps and an auxiliary electric pump) operated everything except the spoilers but could power the spoilers via an interconnect valve.
The independant spoiler system had an electric pump and could be connected to the utility system in the event the pump failed.
The rudder standby system powered by an electric pump could be manually turned on to power the rudder in the event of a utility system failure.
I think that's it but it has been many, many years since I touched an 8.