Ah! So that is what that aluminum is for. Nothing hard at all, just measure and cut a shim that fits between the rudder horn and the spar for spacing. Some work with the snippers and grinder to round and smooth edges then line up holes. Drilled and the now familiar deburring and the part was ready. Notice the larger hole in the R-904 bottom rib. It looks like it ended up dangerously close to the edged, but it's not a critical hole, just a pass-through, so it's ok. I did verify with several other builder's sites to see if I screwed up! Most had similar.
The mystery spare pieces of aluminum in the kit.
The shim will fit in the area below the R-904 rudder rib.
