When I had a Jansport my base weight was 19 pounds for my summer on the PCT. A lot of the old gear was not that much heavier despite what people say or believe. In the old days people carried more of it and often took home cooking items - frying pan etc, and stoves were heavy. You might end up with 5 pounds in a cookkit and a 15 pounds tent, but if you used a 6 ounce plastic tube tent and an aluminum pan over a campfire, you could save 19 pounds right there. Don't forget the cruiser axe and the Bowie knife. If you packed gear with the same eye to light weight, you could go almost as light 30 years ago. Just because that pack is big does not make it heavy. Look at the sleeping bag on top - it probably weighed over 6 pounds.
Jim