While examining this stamp I first thought I had the watermark upside down.
But when I actually put it in watermark fluid, it came up with a watermark that doesn't match what Scott or SG say should be ther.
The stamp:

Back of stamp:
Hopefully you can make out that it is Crown over A (WA watermark
Scott watermark 19, SG watermark 34.

Is there documentaiton of this stamp with this watermark?