I'm sure that hasn't been patched out.
I believe when you combine a Sword of Runes in the scabbard, it produces the 2-hander. Therefore, you want to transform your existing 2-hander into 1-handers, then click combine the Sword of Runes. If you click Combine while you possess the 2-hander already, it will return nothing because the 2-hander is a lore item. Please let us know once you got it.
Also, be sure to enjoy this, because I worked hard on it:
https://www.reddit.com/r/project1999...mouth_for_war/