A number of people in this thread appear to be talking about what I think of as Victorian-style diamond shingles, in which the vertical and horizontal dimensions of the diamond (when installed) are more or less equal and in which all four corners are pointed.
I'm looking, instead, for an asphalt shingle in a more modern style in which the horizontal dimension is about 50 percent longer than the vertical and in which the top and bottom points are flattened or squared off. I'm told that various companies manufactured these under the names French Method, Copper Clip, and Staple Lock -- but none are no longer in production. I'd appreciate hearing from anyone who has suggestions.