Assuming that you have SG Watermark 15 (the C of A crown multiple watermark), then you only have the two options, D117 or D125. The Australian Commonwealth Specialist's Catalogue has a picture showing these differences, with D117 on the left, and D125 on the right:
The most obvious difference is in the shape of the inside of the D. However, you can also see a difference in the top of the curve of the 6. There are three dots/curves in the Original (D117), and only two dots/curves in the Redrawn Die (D125). So, first verify the watermark, then the shapes.