Charles Woodbury Native Trees Collection by Milton Bradley 1905

I am trying to find out more information on this item. This is a folder found in a relatives estate who lived in the same city as Charles Woodbury. There are a couple interesting things about this item. One is that the etchings were made for Milton Bradley Co. That as you know is a game company. I guess way back they commissioned artists to make etchings to inspire artists. Second, I can't seem to find these etchings anywhere except in books. If you know any info. on these please let me know. I guess what I am wondering is if these should be donated to a local museum or put up to auction?

There are 7 sketches. I guess there were 10 when they came out.