Hi Nigel, thanks again for the info. I'm in the US, and here the word cluthra (and occasionally clutha) gets tossed around pretty liberally as a generic term for any glass that has lots of bubbles in it not in a controlled pattern, especially if its internally decorated through the use of colored powders (frit). As a result, here "cluthra" is used to describe everything from WMF Ikora to Ysart, including Setuben and even obscure Czech and Murano, although most people do understand that the terms (Clutrha and Clutha) do really refer to the British product lines with which they originated. Basically, if you've got an internally decorated, colorful piece with random bubbles, you can call it cluthra and people will get the basic idea of what you're talking about, without being precise. Similarly, the terms Czech, Murano, and Loetz can be manipulated to have wide ranging meanings over here which are highly inaccurate but descriptive.
With your help, I was able to identify the mystery vases I was referring to as Nazeing. Two have no pontil, while one does.
Is the piece you show in your last post (above) a Nazeing piece? If not, who did make it? What is the "Elwell find?"
Thank you again.