One thing worth mentioning is that if/when you replace the flipper bushing, be sure to put nuts on the other side of the mounting screws. They come this way, but many times people will leave them off when replacing bushings since the flipper plates themselves are threaded and seem to provide a tight-enough grip on the bushings. Without nuts, the screws will start to come unscrewed over time leading to wobbly flippers, or worse, flippers that rub the playfield. I found this out the hard way when I put some games on location and found multiple bushing screws laying at the bottom of the cabinet only a couple of weeks later.
Also, it might be worth adding flipper alignment info to this guide. A lot of people don't seem to realize that flippers should be lined up in parallel to lane guides. Most that I've seen put a straight edge (or some sort of flat/hard tool) against the lane guide and press the flipper up so it's touching the straight edge, rather than keeping an even spacing between the rubber and straight edge, resulting in a flipper that is tweaked slightly upward.
Great job on the guide, I'm sure it has been a huge help to many people!