So this is Kurse that was given the strength to be 4x Thor strength.
2 Questions.
Is his iron vulnerability a well known fact?
What battlefield are they fighting on? What I'm asking is, are they in a scrap yard, a park, or is this just a featureless environment begging the question of whether or not DOS Superman would be able to defeat Kurse?
From what I recall, Superman was far weaker during the DOS era, than he was a little less than 10 years later than the event. My guess would be that he may have a chance, but I think that without the knowledge of Kurse's vulnerability that he could be in for a lot of trouble, plus if this is a featureless environment, he'd likely have no way of permanently putting Kurse down. Kurse after all had Beta Ray Bill, and Thor beat.