A house built in 1977 usually has a torsion or extension spring system on hardware that's still recognizable to any supplier - not the obsolete side-mount brackets you find on 1940s and 1950s stock elsewhere in the wider area. That's good news for repair costs: springs, cables, and rollers from this era are common stock, not special-order. What does show up often in houses this age is opener wiring and safety-eye brackets original to the house, sometimes past 40 years old, where the sensors have drifted out of alignment or the logic board has simply worn out. In this cold, severe climate, doors from the late '70s also tend to have thinner original panels with less insulation than anything built in the last 15 years, so cold-weather stiffness and slow response from the opener are common calls here.