My guess on the grain bill would be equal parts wheat and barley, and at least 20% cane sugar.
We found an interview with Brad Rogers (Matilda Bay's master brewer), he said it's just 50/50 wheat and barley. Cane sugar would dry out a recipe this small quite a bit. Though I can't personally comment on whether that's appropriate or not for Redback in particular, it seems out of place for a weizen.