This area sits in a severe cold climate band, and that matters for openers in a specific way: lubricant in older chain-drive units thickens in deep cold, the motor strains to pull a door that's gone stiff on its tracks, and over a few winters that extra load burns out the drive gear years before it should fail. On a house built around 1960, the opener is rarely the original - it's a replacement from some point after, bolted to a header and track that are the actual original part, and those don't always flex the way a modern door system expects.
The honest limitation here: if your track or header is bent or undersized for a heavier door, a new opener won't fix that - it'll just fail again, faster, under the same strain. We'll tell you when the fix is the frame, not the motor, even if that's a smaller job than the one you called about.