I wonder if anyone might have the old mini or dwarf zonal Mephistopheles. The description is "Almost a replica of Black Vesuvius, but it grows about 2 inches taller, whilst the foliage is even darker." Here is the description from that book of Black Vesuvius: "Very slow growing, a fully grown plant will reach a height of 4 inches to 5 inches bearing scarlet flowers and bronzy-black foliage. There is another form bearing deep salmon flowers." Bear in mind that this is a description from England and in California it might grow a bit larger.
Anyhow, can't find it available in the nurseries and it may be lost, but also might just be lurking in someone's collection.