Just a few:
1.) a compass......I have a GPS unit, but still use the compass more often than not......batteries won't ever go dead!
2.) Wooden duck calls.......my favorite is the Yentzen shure shot. I think they sound better than the acrylic, and when you accidentally drop 'em in water, they float!
3.) the pocket hand warmers that use the grey sticks that you light with a match or lighter.....don't know the name, but they stay warm for about 5-6 hours. I usually use three this time of year. Haven't been able to find any refills in a while, so when the supply I have is gone, I'll have to find something else.
4.) Wool pants/jacket......stays warm, even when wet, and doesn't "swish" like nylon when you turn to see what made that twig snap
5.) cast bullets........good enough for target practice, and I have taken a few head of game with them. Cheaper than jacketed, and as long as I have a supply of lead, I can make my own even during shortages produced by idiot political dogma!
6) Labrador retrievers! May not be "obsolete", but I still think they are the best, all around dog in the world! Haven't seen any of the "newer" hunting breeds do better. (this last one was a little tongue in cheek).