Vintage sewing patterns are a great resource to have. Whether I am trying to date a dress, or looking for new ideas, I just can get enough of them!
Mena Trott of Sew Weekly recently found a Simplicity 1958 pattern book. She has posted page after page on flickr for all of us to see. It's great fun to view these, and what's even better, the back views are there too. How often do we need to get those details and they aren't available? I think you'll enjoy this new resource, and if you're unfamiliar with Sew Weekly you may want to check that out too.
(the Simplicity pattern shown in this post is from my own collection)