After giving it some more thought, I came up with the one piece of equipment which has made a big difference to me and my hunting; backpacks. Fifty years ago, the best we had available was the Trapper Nelson pack and a tumpline. All the weight was carried on the shoulders and neck. Todays packframes, carrying much of the weight on the hips, allow me to carry more weight for a longer distance than I would be able to with the old packframes.
As far as longevity and medical advances go, this is another thing which, so far, has had no effect on my hunting. I'm 65 and fairly fit but so was my father and my grandfather. serious medical issues prior to the mid seventies don't seem to be in the family make-up. I feel like I have another ten years of hard hunting left in me. After that, we'll see. GD