Andy:
I had forgotten that the 17th on the Old course at Stonewall was intended as a reverse Redan, because we had to abandon our idea for the back tee when it was being built and only put it back into play a couple of years ago. Changing the angle to the right and shortening the hole considerably had turned a Redan into not-a-Redan, but now it is back to being one.
I'd never thought of the 15th Old in that context. The ridge in front of the green is a natural rock ledge so it had to stay; the green itself sits well away from it and is really tiny. The safe play is to bail left and a bit short, and hope for the possibility of a good bounce, but to me that isn't enough to call it a Redan.
I would never call a hole with water a Redan. The 9th Old was based more on the 16th at Augusta, and the 16th green at Pine Valley, which starts low by the water and rises up abruptly to a back tier. You can try to use the big slope in the green to swing a ball around to the left side, but there are lots of greens like that, and they aren't all Redans.
The 17th on the North course, I guess I would call a Redan. I actually told my crew NOT to build a Redan there, but when I got back they had built one anyway. That's what I like least about the Redan ... that so many people who are interested in architecture tend to want to pound that same peg into every hole where it might fit, and even if we do something completely different with the green contours, they are still going to see what they want to see.