The thing about metal chairs like this pair is that, whether they are authentically vintage or reproductions, they still are going to rust and chip. Give them a few years, and you may not be able to tell the difference.
Now, this particular pair are old -- you can tell by the shape, design, punched-metal pattern, etc. Newer ones - considered "retro" -- are usually more solid and are powder-coated in contemporary colors, like brighter reds, yellows, and dark greens. Depending on how much more you want them to weather, chairs like these would probably be better off if they were on a porch or under cover -- rain and the elements will just get them that much more rusty.
