These are what the original set looks like, a bit different than the reproductions. There is also a gasket that is used with the heater install but not the block-off plate (I have seen a couple with it, but not all)?
https://www.flickr.com/photos/advance-design_parts_co/15838946822/in/album-72157631868452754/
https://www.flickr.com/photos/advance-design_parts_co/8129439572/in/album-72157631868452754/