"BTW, inside the distributor cap, the rotor is just missing any post when the engine fires. There's a buildup of green stuff not on the face of the terminals inside the cap, but on the very edge. Is there a solution for this?"

Not sure how you can tell where the rotor is relative to firing unless you have one of those clear caps or x-ray eyes. A bit of buildup on the cap "contacts" (not actually contacts as the rotor doesn't touch them) is normal so you don't have to be in a hurry to clean it off by scraping etc. Just keep them tidy. The gap between the rotor and the cap contacts isn't critical. My car ran perfectly and started first turn of the key with the damaged rotor shown. No blade on it at all. Ran and started the same when I replaced it. (Not with that good one, I don't think that's a Volvo one)