I understand what you're saying and of course credit where its due he did indeed say he remembered making them. But though Timothy would have been a child (being a child if anything sometimes means remembering more, believe me!), he along with both Jonathan and Elizabeth Harris are likely to be the only 3 people alive with as much experience at Michael's work and methods as anyone.
The fact that Tim handled the piece and looked over it, something pictures can sometimes not convey. Describing each process that was gone through as though he'd made it himself. I'm sure that the Harris family have all manner of Michael's pieces both unique and never seen before that we would perhaps reject being MH's work. Just because its not been seen before doesn't make it not MH, but that fact Tim told me this was a method he used on early early pieces means he must have? surely?
On the contrary Sue, I like a debate and about glass, well its more exciting! Until I see another one as apparently there were alot of them made I gather from Colin's quote. Which after scouring the internet I see no Alum Bay with this colourway or indeed shape anywhere. Then I will stick with Timothy's ID of very Early Mdina.
I too over the years have handled many pieces of Mdina both early trial and modern. While my father collects it I deal in it and other 20th century glass and have done so since the age of about 5 or 6, I may have even sold to your good selves at some point in time! Even to me without Timothy's verdict its Mdina, the thickness of it, the wonky top, the bubbles, the shape, the silver chloride. Whilst early pieces are associated with the infamous cobalt blue, there are plenty early pieces I've seen without it.
But as I say, until im shown another or indeed an Alum Bay piece with the same colourway and finish, Mdina is what I will stick at.