Rosie:
This type of work (fused and slumped glass) is often done by a small (i.e. one person) studio. I think you said you lived near Wales, so I would start looking for a small art glass studio near you, or near where you bought it. Having said that, I live near Vancouver, BC, and one of the pieces I have lik this comes from Scotland, and another from Minnesota, although it was bought in Kauai.
Hope this is a start.
David