Back a year and a half ago when I was on my renewed hunt for a set of BFG AT tires for my 16.5" aluminum slots, I ended up finding a set of 16.5" aluminum turbine wheels that come to find out turned out to be off of a guy I grew up with's grandpas '76 K20 and they had a set of Mud King XT's on them that were literally brand new. The guy said they had less than 1,000 miles on them before he took them off when he converted the truck to a dually, and they were stored and forgotten about in a back corner of his shop that is climate controlled under an old blanket. My buddy had just bought a '79 K20 (in hopes of reliving his youth as well) that just so happened to have 16.5" American Racing wheels with a like brand new set of 33" BFG AT's where the truck he bought had been inside a farm shop for the last several years and was climate controlled (mostly) as well so I went ahead and acquired the turbines with the mud kings from guy #1 and horse traded guy #2 for the AR wheels with the BFG's so I could put the like new BFG's on my Aluminum slots. Took all above stated tires to the tire shop close to here that's been in business since before I was born, asked him to demount, inspect, and give his honest opinion of all the above tires and if they were good to make the remount on the appropriate wheels. Called me a couple hours later and said they were all done and ready to be picked up. Got there to pick up said tires and he said they were in actually in pretty good shape with just a little minor dryness at the base of a few of the treads, in nice shape inside and out, but overall he said they were all good and he wouldn't be scared of any of them. But he did say point blankly after telling him the story of how they all came to be that the reason the tires were in such good shape could be attributed to the fact that they were all older compound tires and were also inside and not exposed to the sun, elements, and hot and cold temp swings for all those years. He said they'd be junk if they were and he'd have had some reservations on remounting them. So there's my take on it, if you drag something out of a field that's been sitting for a whole bunch of years I don't know if i'd trust it to go for ice cream, but for something that has sat inside of a building for most of it's life being protected from mother nature.. probably won't scare me as much. I will add that all 12 tires/rims we brought the tire shop were clean and still all had air in them and none were off the beads. But The aluminum slots I wanted new tires for so badly? when I first bought them for my truck out of a cattle barn I am ashamed to admit I probably shouldn't have driven them to the end of town but I put some miles on them anyway while on the hunt for good ones. They had enough dry rotting and big cracking across all the treads that I was literally scared to put air in them half the time! lol I've put more miles on the truck now in the last 4 months than I did in the previous 4 whole years of owning and haven't been scared of my 15ish year old tires since.