Need help buying ralf aust razor

I am thinking about purchasing my second straight razor. My first was a Ralf Aust from SRD. Fabulous razor and I would definitely buy again from SRD, but all they have in a 5/8 is the black plastic one that I bought as my first SR. I want some fancier scales (either horn or black with the silver crown jaw). I went to the Ralf Aust web-site but he has a couple of options that I don't understand. Hopefully you might know the answer. The options are: "With or without serriertem ERL" and "with or without schorkopf". I don't have a clue what these options mean. Thanks.