I picked up this interesting fly book that was made by a manufacturer that was unknown to me. Thanks to Hathitrust.org, I was able to find some information. Henry Bew is listed in T.C. Holland's books "The British Angler's Manual" in 1839 and 1841, but not in 1848. Please see the photos below to see the book and the flies that are in it. By the way, Holland's books show all the flies popular at the time and how to make them. Also, notice down towards the bottom of the list of manufacturers, you will see Maria Ustonson's name.
What a great time capsule, Ron. The condition of those flies is amazing given their age. To put 1840 in perspective, Martin van Buren was the US President and Abraham Lincoln wouldn’t move into the White House for another 21 years.