I don't think 70 Coronet bumpers are reproduced. I doubt it, but you could simply do a very generic ebay search (70 Coronet) which would pick up a lot of items. You'd think a bumper or two would show up on the search if they are reproduced.

The plater that has my Demon bumper is near Hazelton, PA. They did the front bumper on my Dart Sport back around 1990 and the front bumper on my 71 Duster back around 1993. Back then, jobber cost was $180 and they were done and delivered in about two weeks. Now they say 4-8 weeks and wouldn't give a quote. Can't WAIT to see how much the cost has gone up since 1993.