We carry standard galvanized lift cable in the gauges that fit torsion-drum residential doors, which covers the great majority of doors built in Roxborough Park's era. We also stock the drums, bottom brackets, and pulleys that commonly need replacing alongside a snapped cable, since swapping the cable alone onto a worn drum just sets up the next failure.
What we don't carry on the truck is anything for a door outside standard residential torsion hardware, like a commercial-spec or oversized custom door. Those parts get ordered once we've seen the door and confirmed exactly what's on it, which means a second trip. We'd rather tell you that up front than promise a one-visit fix we can't back up.