RH.1 and All,
The Web Site you are looking at is "Classical Glass", the Victorian Opalescent Glass Price Gude, by Bill Banks. He is one of the most knowledgeable authorities in the field. The full Web Site is available by subscription only and, if I may say so, well worth the price of $19.95. Not sure of all the "mistakes and misinformation" you cite. I will admit it is a bit limited on the listings and info for the English glasshouses, but as to the American ones, it is mostly complete and very accurate. The Guide was, and I believe still is, published in book form which I purchased for many years. The CD is nice but, obviously, without updates which is included in the on-line subscription. I think you may want to look at the entire Web Site, not just the "attribution list" before passing too critical of a judgement. My opinions only, of course, but the Guide has been invaluable to me over the years.