Back to the vase in question. I don't know whether it's a fake or not, but I spent a fair bit of time yesterday looking at Grover's English Cameo Glass. To me my studies say the rim looks OK, the colours look OK, some of S&W stuff seemed a little less well-defined than the Webb and there is a similar Webb (marked) vase (shape, design and colours, but 3 inches smaller).
I think the scratchy looking marks may be pencil marks trying to make the mark stand out more. These hot-stamped marks are quite hard to read never mind photograph ( I have a marked Webb Burmese).
It looks like uranium glass to me; that might be the clincher.