Hi, Many thanks for those ebay links, not 100% sure they are what Harry Dyer was describeing but maybe the first one is ?
I have listened to his words again and he says " a paperweight with a shadow in it, like it has engraving inside it.................. you get a spoon with very wet pot clay and pour it on , turn it and let it run down and it comes out just like a silver leaf or something "
He uses the term "bottle maker's paperweight" a few times.
I do know he was interested in paperweights and made one to his own design whilst at Whitefriars called the " Eye " . This has a small area of coloured glass that looks as it it could have been dropped or poured onto the top and then covered in another layer of glass .Perhaps he got the idea from the clay ?