Hi Bernard
Thank you for your help, I do not have this piece, it is in a secondhand shop which my wife and I vist, were we have found some nice glass and china, the syphon has a dimple pattern and is quite heavy, I will see if it is still at the shop when I next visit, and try and get a photo.
In this shop I found a piece by Greener Reg No 138501 a double dish with center handle.
Tony H