Ward Lloyd was a long standing pal of Peter (oldglassman) - and from memory Peter thought highly of Ward Lloyds expertise and contribution to the area of Georgian glass - but then Peter was an acknowledged expert on the stuff too.
Having deep pockets does help of course, and it's back to the old adage that there's no substitute for handling the stuff, which is easier if you are able to invest in the real thing. Fifty years ago I'd suggest glass from that period was undervalued - now it's probably overvalued - old seem to equate to big bucks, which is fine provided that what you're buying is genuinely old - trouble is that the market now has much glass of questionable age, often described as C18 - C19, so buyer beware.
W.L. comments about colour are likely the outcome of an experts view after handling vast amounts of old glass, which is understandable, but I also still feel happy about buying something with grey colour - the implication being that by the law of averages a grey glass is most likely to be old - WITH THE PROVISO THAT THERE NEED TO BE OTHER FACTORS contributing to that decision of age.
It's a known fact that some makers, post 1860 - coloured the glass deliberately - blue or grey. Probably best to start from the premise that a piece isn't what it seems, and then use all the usual indicators to assess whether genuine or not. Sellers view the word 'Georgian' as such a cash cow, that if something shows the slightest age, then it qualifies.
Bernard Cavelot once took me to task for suggesting he was an expert - I still think his knowledge in some areas was almost second to none, but he was adamant that the appellation didn't apply to him, and I had the impression Bernard didn't favour those who, like me, quoted from books. His work ethic was probably that you should open you mouth only if your knowledge was acquired via first hand experience, but we all have to start somewhere and sound knowledge often comes only with age. The word certainly doesn't apply to me. But I expect there are folk who revel in the title.
I bought a first half C19 water jug yesterday, with a noticeable grey cast - will try to post a picture for comparison with C20 bright white glass.
IIRC, The Miller's Check List is the Mark West little volume, and I would suggest is reliable, on the basis that I know there are folk who hold West in very high regard.
Even without the skills of a University Challenge finalist, it can be very satisfying to walk round an antiques emporium and almost laugh out loud at the glaring errors of description from sellers who obviously have little knowledge of their wares, but reaching that position takes time to learn - via books and experience.