This week we installed more trim pulleys and worked on the control yoke chain and related parts. Working aft, we installed the two pairs of trim pulleys that run just under the cabin floor. The parts manual calls for another pair at the aft end of the baggage compartment. The maintenance manual does not call for this set and there is no bracket for it. That, plus the fact that we only have 12 pulleys rather than the 14 shown in the parts manual, has led us to conclude the parts manual is wrong or might be referencing an earlier model. We looked at hooking up the new trim chain to the new cables, but it seems we may need a special tool to do that, so we set it aside for now. We then got into the complex control yoke chain and sprocket system. It needed cleaning and upon inspection by one of our A&Ps a couple of issues were found. The safety wires on both turnbuckles were the wrong size and two of the clevis bolts with castle nuts lacked cotter pins. So we ended up taking a lot of it apart and cleaning everything. Complete reassembly will happen next time.