Because we're coming from Tukwila, about 4 miles out, the truck carries torsion springs in a range of wire gauges, not just the common modern sizes, since older doors in Normandy Park often need something closer to what was original. We also carry track sections in a couple of widths for exactly the mismatch problem described above.
What we don't carry is a way to match decorative original hardware - if a door has hinges or a handle from 1962 that the owner wants to keep for looks, that's a specialty part we'd need to source separately, and we'll say so up front rather than promise a same-visit fix on something we don't have. For the mechanical parts - springs, cables, rollers, openers - the truck is stocked to close most jobs in one trip.