Will do. Off to a friends tomorrow night to check out some hinge setups that will help. Nothing I came up using what I had around with filled me with confidence

In the meantime have measured and carved into the first wing to work on servo installation. At this point all will be internal, but set up so in worst case can quickly copy the aileron rigging with external control horns.

Only issue I can see is fitting the servo to the second wing as they will both turn the same direction. If too much trouble will dig out a reversing Y-lead from spares and check the geometry follows through the range. BAD if one flap extends more than the other at any deflection.