Ideas yes, but nothing conclusive.
Having spent some time making comparisons between this frosted example and the two pictures in Slack, my personal opinion is.............
This one bears more of a similarity to the 'translucent green' example in the book (which is without proven attribution - but thought to be Greener) - than to the pair of Brown Marble ones which are known to be Greener (first factory mark).
The reason being.............comparing those in the book, the most notable difference seems to be the height of the mane. The brown examples show only a slight rise over the head, whereas in the green lion the mane rises sharply over the forhead to more of a domed look. I'm sure there are other more subtle differences, but difficult to see from the pictures.
However, from what I can see, this frosted example appears to show less fine moulding detail than those in the book. I suspect that Simba doesn't have a copy of this book, and we aren't given the height of this one, so unable to compare with Slack's comment that the green and brown examples are both 15.2 cms. (6") - which seems odd, since he says that the green ones were made from a slightly larger mould!
Although there are several 'lions' in Thompson, none is in this pose i.e. paws resting on the draped shield thingy (although funnily enough Thompson does show a pair of 'frosted' lions (Landseer style) which are attributed to John Derbyshire. Lions in general seem thin on the ground in all the other books I have, so no help there. They weren't thin on the ground at Birmingham on Sunday - but prices were like telephone Nos.
I get the impression that paws resting on the ground was a more common design, and on balance it may not be unreasonably to think that all examples produced with 'paws up' were Greener - but that's just a personal thought. Positive attribution for this one may remain elusive, unless someone can find the exact pattern in a book.
Having spoken to Raymond Slack about his omitting reference to glowing glass (aside from his quoting extracts from the Pottery Gazette where given ingredients include uranium) - he did apparently have a reason for calling pieces 'translucent green' rather that saying uranium green, as we might now do.
Although ingredients for such products as Burmese Ware, Sowerby's Patent Ivory Ware and Davidson's Yellow Pearline obviously included uranium, it seems that it was Burtles and Tate only who actually marketed a product which had a trade name of 'Uranium' - and this was one of the colours in their Topaz range (presumably it was green - I've never seen it). Outside of this, the use of the word uranium was confined merely as a word used to describe one of the constituent chemicals in certain types of glass - not a word used to describe any glowing green glass, as we do. The Victorians didn't have u.v. torches, and so didn't attach the same meaning to glass containing uranium, and Slack followed that line of thinking, and didn't make reference to uranium green pieces in his book.
With his experience of pressed glass, is Bernard able to comment on this 'lion' issue in any way - or anyone else for that matter.
P.S. sorry this is so long, I really try to be brief, but it just doesn't seem to work.