In Greg Daspit's post of Feb 17, his pic cockpit.jpg shows, in bottom center, chain as I described in an earlier post -- similar to a bicycle chain. Flaps require precise control in both extension and retraction, so cables are inefficient. Chains are much better for the task. The pic chain was most likely under the floor of c/n 1021.
Tim, I see your chains on the reef, but I don't think they are L-10 control chains. And, they're too long. (Did Lockheed Burbank use chains or straps to secure the extra tanks in the fuselage of c/n 1055?)
Regards
Mike