Given the climate band here - cold, and severe with it - the parts that fail first are galvanized torsion springs, steel rollers, and weatherstrip on the bottom panel, all of which we stock because they're the ones that go on Midland-area doors built between 1952 and 1994. Breckenridge sits right in that window at a 1962 median, so the springs and cable drums we carry on the truck match what's likely on your header.
What we don't carry: obsolete one-piece hardware for doors that predate the torsion-spring era, and some older extension-spring assemblies that haven't been made in decades. If your door falls into that category, we'll tell you straight rather than jury-rig a part that won't hold in cold weather - and on some of those older units, full replacement is the honest answer, not a repair.