There's a (poor) image of my vase here - it's called "Lime". (I got it cheaply in TKMaxx, purely for the label and it being Dartington, according to the box it came in. I suspect "his lordship" may have binned my box. He tends to leap upon boxes, tear them up and bin them before I can hoard them. But they are a pain and do take up a lot of space.
It's the same shape as your vase, the decor is quite different, I reckon your bit looks better made too, but the base finish isn't too dis-similar..http://www.englishchinashop.com/dartington/innovate.asp
I don't think yours is Caithness - wrong finish on the base, completely.