Welcome to the forum.
There have been lots of soft and hard top manufacturers over the years. By 1980 I think most had switched to fiberglass, although I wouldn't be very surprised if someone was still making steel tops.
I think all tops from 1976 to 1983 are interchangeable. There was a slight change to the windshield in 1976, so earlier tops dont' fit right. (I think).
You might find manufacturer info in the window glass - it's frequently etched in.
Otherwise, take a few photos and post them here, and maybe at www.earlycj5s.com
- those guys can probably tell just from a glance.