Received a reply, unfortunately I don't think it will help much sorry:
"I actually do not have the item any longer, sold it to a collector who also had a blue one like it. From memory the vase could not be removed from the metal holder as it had a glass ring above and beneath where the metal ring fitted. It was all part of the same vase not separate. I only remember this as I planned to take it apart to clean the vase but was unsuccessful. Further than I am afraid, I cannot help you."