The truck carries what covers most commercial calls in a building this age: torsion springs in common commercial sizes, galvanized cable, ball-bearing rollers, hinges, standard-lift and heavy-duty commercial opener units, and photo-eye safety sensors, which are required hardware on commercial doors and fail more often than most owners expect.
What's not standard stock is anything custom-width, anything with a discontinued opener drive, or specialty weatherstripping ordered to match an original install. Given the mid-1980s construction window most buildings here fall into, that's less common than it would be on a much older building, but it isn't rare either - forty years is enough time for a manufacturer to stop making the exact part that went in originally.
If a part isn't on the truck, the tech will say so on site, quote what's needed, and let you decide whether to wait on the part or look at replacing the section or the opener instead of chasing a match. Sometimes replacing is the cheaper, faster call than sourcing an obsolete part - that's worth saying plainly rather than letting a repair drag.