Several years of effort have gone into refining the design of the International Linear Collider (ILC). Evolution of the design has resulted in adoption of a more sophisticated waveguide system for delivering RF power to the cavities. In particular, the desire to eliminate parallel service tunnels along the Main Linacs led to the proposal of the Klystron Cluster Scheme (KCS), which involves bringing the combined power from groups of klystrons down from the surface at several locations in overmoded waveguide. Additionally, to increase superconducting cavity yield, the acceptance criteria were relaxed to encompass a +/- 20% range in sustainable operating gradient, which required tailoring of the RF power distribution to the cavities. Designs and prototype testing of some of the novel waveguide components developed to accommodate these changes are described here. Show Partial Abstract