Hi Dave,
Came back yesterday, looked at the board just now, scoured for hyacinth vases, and Bingo!
I have this one myself as well, bought it in England (and so for me it's English for the time being) and nor the dealer nor me could really place it.
Checking it literally from top to bottom it could be anywhere between 1920 till 1940 and that is purely going on a hunch. Not much help, is it?
The cup is rather unusual for a hyacinth vase, almost like a tulip,and no other vase that I know of has this kind of cup. So if it has to be sold, go for that aspect, I did when I bought it.
Good luck, Patricia