In addition to all the usual parts, I ALWAYS replace the flipper [shaft] bushings. They are often cracked or worn and the damage is often not obvious. Hard to go wrong with ordering the flipper kits from Steve Young (PBR). I do this for the Gottliebs and other makers as well when I do rebuilds. They come with absolutely everything you need to do the rebuild and no need to scavange parts from the old flipper parts pile. I also think that their prices on the rebuilt kits are very reasonable.