Son of a gun, I was researching 1970's outdoor equipment for a show and came across Google Magazines. They have Backpacker Magazine, all issues online going back to the early 70's. Also all issues of Old House Journal, Field and Stream back to the 60's, Log Home Building, Boy's Life, Mountain Bike, Bicycling, American Motorcyclist back to the 50's and a lot of others.
You could spend hours going through these...
Google Books