Never mind Otis - this is all the fun of glass collecting.

Your ISBN reference seems to be correct Otis - it's Charles Hajdamach's most recent volume - C20 British Glass - although obviously it covers the U.K. only, but essential really if you have the remotest interest in British glass.
As with his previous book, this is again too heavy for a single volume, but publishers save money where they can I suppose. Attached pix of my copy which eventually cheesed me off to the point where I'm now re-binding to make two volumes. One volume already resewn, with supports - and the other waiting to be sewn. New marbled endpapers - probably unsuitable - but any port in a storm - and the brown paper waste sheets helps to protect the text block until the end papers are pasted to the boards, when the waste sheets are torn free and thrown away.
If you don't have this book, I'm sure there are 2nd hand copies on the internet for not too many shekels, and it really is worth the money, and when you do get a copy you'll be able - hopefully - to see the difference between period bubbles and modern bubbles
