The 58 was a great old shotgun in its time, well it still is I should add.
I think Remington simply changed the way their guns worked to be more user friendly and easier to maintain and most likely cheaper to make. The operating systems as to gas and functioning are totally different, the 58 needed you to adjust for high power or low power hulls, the 1100 required no adjustment. I don't think the 1100 has the "handling" qualities of the 58, but I feel the 1100 is a superior system in the long run.
I wish I HAD hung on to mine, but I didn't.