I have a rifle scope with "Meiji 4 x 20 image moving nitrogen filled" clearly written on the barrel. I inherited it from my father. I can not find any information about it online. It might be pretty old, as my father made several trips to Japan between 1962 and 1974. Meiji Techno specializes in manufacturing high-quality optical microscopes for scientific, medical, and industrial use. The company does not usually, or currently, produce riflescopes.
I have requested information from Meiji Techno about this scope and will revise my asking price based on their answer, if necessary.
If you are familiar with one of these scopes and would like to share your information I'd appreciate that as well