yes, I see that the UK bookseller chain Waterstones has also now decided to drop them, so you're in good company jp - nonetheless I shall remain true to the cause and cling nobly to English grammar, like what she is supposed to be writ. And now for something contentious, but perhaps helpful

Fakers and those intent on deception go for art glass and pretty glass that they know will appeal to Buyers who care more about looks than historic interest or value, so they choose 'Murano' styles (aventurine and all that jazz) to copy and sell. They know that a large part of their market isn't over versed in the subleties of manufacture or factory accuracy, and so scrape the base in one direction only, as probably most of joe public who buy this type of glass aren't aware that time and tide produce wear marks in 360 degrees, and it's true that boot sales are full of imitations and punters who buy cheaply, often with no other intention than posting on ebay for a quick profit.
Most of us have bought hurriedly and cheaply, in the dark, on a cold morning, something which we believe, secretly, to be of high value - only to get home and realize we've goofed. Nothing wrong with that, unless of course you repeat the mistake. I suppose we're all greedy and it's the reason why we rise at some ungodly hour in the dark and cold looking for real bargains, and doubtless Chris thought he was getting Murano. What's that phrase....'if it's too good to be true, then it probably isn't'.
Of course those of us who don't buy high end art glass, or pieces that are fashionable, are less likely to get our fingers burned - on the other hand we might have boring collections

However, as we are always saying, 'if you like it, and it's cheap, then buy it'.........what does it matter from whence it came, or whether the scratches all run the same way.
The problem comes only if you are buying expensively and don't have the expertise to back up your intuition.
quote from jp..........."another point that i figured out a while back (seriously John

) is the wear should only be on the high points that touch the surface its resting on"........and whilst this is obviously very true, and one of the first things I look for, I believe that sort of effect can be faked without difficulty - give me a few sheets of wet and dry paper and I'll wager that I could produce authentic 100 year old wear on almost anything.
A more subtle pointer is to look for wear on the extremities of the piece - something a faker would almost certainly overlook, but of course less obvious or absent on glass made recently.
So, moral of the story - know your glass if you're buying in the dark - or, alternatively, buy genuinely interesting glass - anything with real history, and which the fakers have no interest in and you can assess more accurately

Or just buy what you enjoy looking at.