My distant recollection of what I thought was a Don Marine cast rudder stock is that there were no lines. The blade was held down by a spring-loaded plastic roller which engaged a cut-out somewhere in the upper part of the blade. I borrowed one at Campbeltown many years ago. Unfortunately, on a high speed plane it tripped and bent the stock so I have no experience of the uphaul arrangement!
Thanks Norman. I think the way forward is to ditch the spring loaded nylon locator. I intend to add to it’s “axle” a “bobbin” of some kind to overcome the friction inherent in the routing of a down haul.
The one thing these stocks have going for them is their stiffness. Seems good.