Hi to all
The following stamp is hard to get a good picture of the watermark and this is the best I could
Now on each of the stamps, it can be seen that the sideways watermarks are as follows, one is to the left of the CoA, and the other is to the right of the CoA when viewed from the back, therefore one has to be the famed SG253aw. Sorry but this is the clearest photos I can get of the watermarks.
However, I would think that this stamp is not as rare as it used to be, as there seems to be a few more copies turning up these days.