Actually, if they were made from metal and had convex/bubble glass, then they were much much older than 1980's. They could have been from the early 1900's, which this one most likely was. There are also ones that look similar but were made from plaster instead and then painted to look metallic, but I'm not sure when they started making those.
I absolutely LOVE this! And what perfect timing! The past month or so I've been wanting to re do my bathroom in a sort of mermaid,pirate,beach theme. But not really wanting anything old lady-ish (plastic pastel sea shell stuff) or childish/cartoony, I've been brainstorming handmade items. And then the other day I thought "Wouldn't it be great to make some things out of beach glass like I saw decorating the porches in Key West?" Only, I live in Houston and don't get to the beach very often. So....hmmm.... And then I saw this! I will definitely be buying something from your etsy in the near future!