Doors installed around the early 1960s in this area are usually steel or wood single-panel or early sectional units, hung on hardware that predates the extension-spring-cage safety standards that came later. If a spring on one of these lets go, it can swing the whole door hard, and we won't put a new spring on an old door without checking the cable drums and the end bearings too - replacing one worn part on 60-year-old hardware and leaving the rest is how you end up back out here in six months. On the newer side of South San Francisco's stock, doors are more likely steel sectional with torsion springs mounted on a center shaft, and the common failures are different: broken torsion springs, worn rollers, and openers with stripped gears rather than the cable and pulley failures you get on the older single-panel doors. We don't carry stock for every old hardware pattern on the truck - if a 1960s door needs a part that's no longer made, we'll tell you that straight and talk replacement instead of pretending we can special-order our way around it.