We're driving from Costa Mesa, roughly 19 miles to reach Norwalk, so factor that into how soon we can be at the door - we don't have a branch or crew stationed in Norwalk itself. Once we're on site, a straight spring or cable replacement on original hardware usually takes longer than the same job on a newer door, because of the bearing plate and track inspection that a 1957-era install calls for. If the opener mount or the track brackets need attention too, that adds time on top of the spring or cable work itself. We won't quote a fixed number of hours here since we haven't seen your specific setup, but we will tell you upfront, before we start, roughly what the job in front of us looks like.