Discontinued hardware sourcing
That matters because a door from that era usually runs on hardware nobody stocks at the big box store anymore - short-stem rollers, side-mounted torsion units, openers with chain drives that have been replaced twice already. Our calls break down into a few buckets: broken torsion springs (the single most common reason a door won't open), opener boards that have given out, bent tracks from a car bumping the door on the way in, and panels dented or rusted through on doors old enough that matching paint isn't an option.