In order to give the skin a uniform appearance, I marked a 10mm line out from the holes on the skin and trimmed the edge using the snips. I also cut away the overhanging metal from where the skin touches the tip rib. Gave the edges a good filing (and cut myself in the process).
One lesson learned from this: get an air riveter! My hand was sore and blistered after all that riveting, and I am sure it is nothing compared to the amount needed for all the other kits. After a little hard work, the rudder was complete: