I have said for many years that the 1970s were generally a cultural low-point for many things here in America: fashion, music, cars, TV, & hairstyles to name a few. However, I believe that the 1970s was the Golden Age of Lawn & Garden Equipment.
Many manufacturers made spectacular equipment during that period...truly built to last decades. If I was looking for a "new" mower, I'd would seek out a Deere 140 from the early '70s. Fantastic machine.
Today's lawn & garden equipment is built to a specific service life. That is unfortunate.