I listened to Jackson Crawford's version of Volsung Saga, on audiobook. In it, Sigurd first meets Brynhild in a tower after slicing off from her the magical chainmaille that kept her in Odin's sleep spell. I do not think his version mentioned that Andvaranaut could locate or generate gold. I think he pulled from the Codex Regis. Fascinating to see all these different versions!
Dr. Crawford is a true expert on the material, though I haven’t read his version. There are several variations, and I mention a few in the introduction portion of the video. It’s actually been a while since I listened to my own video, but I may have reviewed some of the differences as well. Though I could be mistaken.
I got this under my suggestions recently. I mostly knew about it thanks to the Ring der Nieblungen from Richard Wagner and from Wälsungenblut, so it's nice to learn more about the root of the stories.