In view of Glen's suggestion, I forwarded these pictures to Colin Green at Alum Bay, and am now extremely happy to say I have received his reply as follows:
"Hi Paul that is a one off piece I made quite some time back .
I would say 1999 ish.
It looks like a purple with silver leaf and a strap and then oxidized and iridized.
Regards, Alum Bay Glass"
So, my sincere thanks again to Colin Green for his very generous help - also for Glen's suggestion of Alum Bay in the first place - which feel certain I would probably not have considered. Grateful if the mods. will now move this to the appropriate place, and my thanks to everyone who contributed.