I have a mans gruen very-thin. I'm wondering its possible age, and is it a collectable? It is not gold or precious metal but it still works. thanks
You will not be able to get a precise age but if you bring it to a jeweler, he might be able to tell you what decade it is from.
Gruen watches are collectible. It is a smaller niche than other brands but to the right person, it will have collectible value.
To get an idea of the value, look at Cooksey Shugart's book, "The Complete Guide to Watch Prices".