I'm only 40 but started loaded touring at age 15, so I guess that's a jumpstart. I never saw bikes as classic as these either, but I think the "race bike syndrome" had already begun in the USA before I really got into touring, which was around 1985. As a matter of fact, my teenage friends clowned me because I chose the above Trek 720 over a racing bike. The funny thing is, I'm still riding mine, they aren't riding theirs!
I'm actually such a fan of the classic touring bicycle that I own a coffee table book titled "The Golden Age of Handbuilt Bicycles". http://www.bikequarterly.com/goldenage.html
I'm looking through it, and basically the fenders came in the styles that are still available today, as well as some interesting styles that were definitely custom. The first hammered fender shown in the book is on a "Shulz" bicycle in 1935. The first modern diamond-framed bicycle in this book with hammered fenders is a 1946 Alex Singer and then a 1946 Rene Herse tandem, and a Rene Herse Camping bicycle from 1949. They probably showed up earlier, but this is the earliest photographic evidence I could find.
My favorite from the era is a bicycle by A. Faure, who was a watchmaker, and the bike was built sometime between 1948 and 1952 (depending on the publication):
http://www.bikequarterly.com/images/faure.jpg Note how the rear rack is integrated as part of the fender! Detail photos of this bike are amazing, with components created by the watchmaker such as a speedometer, clock & bell.
Here's a late 40's C. Bailleul I spotted on Flickr, also with the integrated rack on the rear fender: http://www.flickr.com/photos/10703870@N06/4716338082/in/gallery-50271552@N06-72157625097501075/
The Zepplin-style fenders show up on a 1950 Rene Herse Randonneuse bicycle. I couldn't find an online picture of the Randonneuse, but in the book they are weathered in a bit, and they look great.
I found some other photos and descriptions online:
http://www.reneherse.com/AlexSinger1947.html (note the URL...Rene Herse has been 'reborn' in Colorado and continues to make amazing bicycles)
http://www.bikequarterly.com/images/Schulzbrake.jpg - Detail of the 1935 Shulz.
Hope this helps,
-Court