The ring is not suppose to be welded.They usually have 2 bolts and 2 little metal plates.One either side (toward the back of the ring)to hold them onto the base.Then at the front there should be (On the ring)folded up pieces to help hold them on.The rings are a fairly tight fit,this normally is enough to hold them on tight.Yes it would have been available at the same time that Corvette was. There were others available at the same time but without my green book with me at the moment I can't remember them all.
