Don't know about the first "aerial photo."
I enjoy rereading these books from time to time. Some aspects remain eternal, like the authors' love of the outdoors. Others hark back to a different time, like when external frame packs were the standard. And others need adjustment for inflation, like the prices we paid for gear. The numbers may look like exceptionally cheap bargains. But when you run them through an inflation calculator you realize how expensive some of that stuff was in today's dollars.
Thanks for the reminder to revisit some of the favorites in my [small] library.