The catalogs for the Ultima Superleicht never seem to show the tubing other than listing it as manganese molybdenum. I think the Ultima may also have been sold with 531 as multiple examples can be found. However the catalogs seem to be missing for those. The Ultima Superleicht also shows the head tube lugs as chromed, where Ultima's are usually painted lugs.
It is difficult to pin down Austro Daimlers with the catalog gaps. 52telecaster got one in an unusual color. also not in the catalogs.