Managed to get hold of a March 1974 Coin Monthly, which was one I suddenly realised was missing. Lo and behold there is an article in there about the 1858/3 penny, by one L.J.Bamford, who I assume is actually the late Laurie Bamford. Excellent article which I've photographed so it can be read by those possibly interested in it.
He also mentioned the 1854/3.