I guess at my age, I quality for the tittle of Grandpa Gatwood.
If I were going to do this, I'd make full use of modern technology and light weight materials for tarp and pancho. Since campfires are strictly forbidden on most of the A.T., I won't be making any fires. That leaves out all the husky broad swords the survivalists swear by. I'd maybe bring the smallest alcohol stove I could find just for boiling water for morning oatmeal and evening freeze dried whatever.
Knives.
Since it's mostly just walking up and down hills, on a well marked trail that by mid summer is more like a suburban park than a real wilderness, I'd go with what my normal suburban edc is. My peanut, a Pattadese, or an Opinel. Probably the most use for a knife on the A.T. is very similar to suburban use, opening packages and dealing with food. With no campfires, there's no chopping or other wood processing to do. For all those years I packed a Randall number 14, and used it to open a pouch of Mountain house Chicken Al La King to pour in some boiling water, was a total waste.
Well known back packer and author Colin Fletcher, who wrote the many versions of "The Complete Walker" used a Victorinox classic on many of his adventures. This is the guy who back packed the length of the Grand Canyon, so he's no rube of fake. Other times he carried a larger SAK, like a tinker. With modern light weight gear, there's really no need for much knife when back packing. By virtue of the sport, you already have shelter and sleeping already taken care of. I'd be going the Granny Gatewood route with as ultra light as I could. At my stage of life, a 20 pound load seems about it. Pass the big trash bags please!
Carl.