And to add to those points, it is very commendable that Cyril Manley did not repeat those early errors about Monart / Vasart when he wrote Decorative Victorian Glass
(first published 1981). Instead, within that book, and across the wide range of glassware he covered, he gave his reasons for much of what he stated particularly where he knew it was not the general opinion of others. So, in that respect, some 10+ years on from the Spinning Wheel articles, it certainly appeared that Manley had gained new information and presented it as such.
However, those of us who like reading the older works must always take care to understand that some of what was stated may not be accurate, but that without reprints or new writings on the same subjects, we may not be aware of what was and was not factual. And in that respect, things have not changed ... except that we now have forums like this and other internet sites to help us more quickly recognise the mistakes that still get through.
Returning to Manley's earlier writings, here's part of his minimal comments on Monart / Vasart as given in Collectible Glass Book 4 - British Glass, published by Wallace-Homestead Book Co., Second Printing 1978
"... To the best of my knowledge, Monart was never signed, but always marked with a gold paper label."
We now know that some Monart is signed with an acid mark. But at least Manley was good enough to point out that it was his best knowledge at that time.
"... Vasart, made by the Strathearn Glass Co, Ltd. City Glass Works Crieff, Scotland c. 1947"
This shows the ease with which information can become distorted, perhaps through editing, typographical error, or just poor review. An original copyright notice gives 1968 as the year in which I suppose the book was first published. By then, Strathearn Glass had been registered as the new company name (out of the former "Ysart Brothers" and then "Vasart Ltd" companies) for at least three, if not four years. But Manley seemed to state that items of Vasart made in c. 1947 were produced by Strathearn!
These examples can give us all a big hint at what to be careful about when we put anything in writing, even if it is just general comments in an internet message board.
By the way, I think that had Cyril Manley been with us now, he would have loved this form of communication and would have been one of the main users of the GMB.