Originally Posted by huddy
My newest Nikkor lens is ca. 1972, oldest about 1966 or 67. They range from one in 98% condition to well used with lots of shiny aluminium on the focus rings. A couple had to be disassembled for new grease. They are all in 100% functional condition, with silky smooth focus and aperture rings.
The plastic lenses are cheap crap for people who are willing to throw something away instead of having it serviced - they could have been made of metal, and still work in AF mode, but that would have been expensive.