Vintage American Optical Company Brinell Microscope Made In USAI am not sure of the age of this microscope, the serial number is 250870There are 3 tags that came attached to microscope of parts purchased from 1976.I do not know anything about microscopes, the slides do not always move when you turn the dial, if you help push them they will move, may need to be cleaned and lubricated.This item is sold untested as-is for parts or repair, because i can not test the item properly.Please se...e photos for details, I try my best to make notes of any issues. Thanks for looking at my item, and please feel free to ask any questions you may have.