A torsion spring under load can put someone in the hospital, and on a house this age the spring, drum, and bracket are often original - meaning the metal fatigue you can't see is exactly what makes a DIY spring swap dangerous here. Lubricating hinges, tightening loose track bolts, and testing the auto-reverse safety feature are fine to do yourself and worth doing regularly in this climate, since the marine air speeds up corrosion on anything left dry. Replacing a spring, a cable, or the torsion bar itself isn't a weekend project - the tools most people don't own, and the injury risk is real. If your opener is original to a 1970 house, don't try to rewire or rebuild it either; parts for that generation are getting hard to find, and we'd rather tell you that up front than have you discover it halfway through a repair.