Metal Glider w/2 chairs

Hello.
I've been trying to find someone who might be able to help me identify an old patio furniture set which includes a 2-seat metal glider and 2 chairs.
We aquired them and they've seen some "weathering" over the years so we are in the process of restoring them but I'd like to know the era they are from and the maker? I haven't been able to see any markings yet. The whole set is made of metal.

Thank you.