Yeah, Garrison is probably the foremost Austrian macroeconomist. Check out his Time and Money resources if you can. The one specifically on capital structure doesn’t seem to be available in the Mises.org resources, but is in the store. His short overview of general macroeconomic theorizing (by the same name) is available here (but the writeup there appears to be for the book). I would also check out his lecture/slide resources if you haven’t yet. They’re excellent.
You may also be interested in Theory of Money and Credit and Mises on Money, although they’re obviously less focused on capital theory.
