We don't take every job, and we'd rather say that plainly than find out the hard way on your driveway. If a door is old enough, and the track hardware or panel is discontinued, sinking money into a patch repair sometimes costs more over two years than replacing the door once. We'll tell you when we think that's the case, even if it means a smaller job for us that day.
We also don't do structural framing work, electrical panel upgrades, or anything that goes beyond the door, opener, and track system itself. If your problem traces back to the header or the wall framing around the opening, that's outside what we handle, and we'll say so rather than taking the job and figuring it out as we go.
And we don't guess on parts availability over the phone for doors with hardware patterns from the earlier end of that 1938-2007 build range. Some of those parts take time to source, and we'd rather confirm before we promise a date we can't keep.