That will be the Weyl patterns. As I wrote in the article about 10 years ago, I think they are mostly unique with the exception of the aluminium pieces documented in the Murdoch sale. There was also an 1887 (unspecified metal) penny listed in the bronze and copper section of the Cholmley sale in 1902 which I found after publication. This sale took place less than a month before Murdoch died, and it may or may not be the same as the one that was sold in the latter's sale. Whatever, it debunks the theory that the Weyl patterns were struck especially for Murdoch, as it is inconceivable he would have disposed of something produced uniquely for him whilst keeping the rest.
Freeman also omits those struck in tin.