As suggested, I did contact Ron Wheeler - and, as you might expect he has graciously given his thoughts on this piece - although, as he comments, we are not necessarily much further forward:
""Hello Paul,
Well now, interesting, and not easy to identify. One reason is that your image file is so large that I cannot see it in whole form on my screen (
I did in fact rectify that issue However as far as I can judge it does not coincide with a surface decoration which matches the shapes of the period of the shape of the design i.e. the shape is that of designs by Michael (Harris) up to around 1980 but the decoration has similarities to those produced after 1988 in a similar style to the Nightscape range designed by Mike in that year and still on the range produced at the studio (look on the Studio website).
However Tim(Harris) did produce some specials in that shape in 1993/6 so it does not preclude the making of this one.
Now my only other suggestion is that is could have been made by one of the glass makers who left and started his own studio not far away on the island. His name is Chris Lucas and traded as Touch of Glass but having been schooled at the studio (I.o.W.S.G.) all he produced was his own version of a well established product and so was doomed to failure - which he did.
He now works again, when required, at the studio and his wife is one of the Studio accountants independently.
So in conclusion you are right, it may never be positively identified. Sorry about that. However if you could reduce the file size so that I could see it in it's entirety it may help.
Hope that is of some help.
(at this stage I reduced the image size)Well personally it does look more like those I have seen by Phoenician Glass but if they say no then they should know I guess. It does not actually match those from Chris Lucas but you can never say 'never' in such cases - Other info. still stands.
However I always quote that 'it is impossible to know everything about everything and very difficult to know everything about something - because there will always be someone who actually does.
Best regards. Ron""
I have removed a very small amount of text from Ron's reply (not relevant to an id) - but the above is 99% of what he has said, and again, my thanks to him for sparing the time to reply.
Might I ask please that the Mods. now remove - from the subject heading - my misleading reference to Royal Brierley. Thanks.