Like others have said, the powder inside the cans will tell the tale. I've been tapping into a huge stash of handloading components accumulated (hoarded) by a child of The Depression who now spends his days reminiscing about his stint in the post-war Army and then working as a ranch hand in Wyoming right after WWII. Some of the powder cans looked exactly like the ones you pictured. Some of them, cans of 4064 made by DuPont in the 60's-70's looked worse. So far, no issues - I've shot a helluva lot of it and in the case of the 4064 I wish I had more of it, my .30-06's love it. There's even about a dozen unopened cans of various Herter's powders from the 60's that I'm very curious about but am a bit leery of only because data for that stuff is a little thin on the ground these days.
All of this hoard was stored in a decidedly un-climate controlled wooden garage, and has suffered three to six decades of wild fluctuations of temperature/humidity which only denizens here on the shores of the Chesapeake Bay will understand. "Store in a cool dry place" warnings were completely ignored by the old gentleman, but knock on wood I haven't encountered any components yet that have gone sour.
As for "who shoots .32-20 anymore?" Well, I do and would surely love to have more components for it. Please keep me in mind if you decide to dispose of it!
Side note: there must be at least half a ton of #9 shot piled out there, the canvas bags rotting and the shot acquiring a lot of oxidation. I've tried reclaiming it by vibratory tumbling with fresh graphite powder mixed in, and that works but is time consuming and I don't shoot skeet anymore. I think I'm better off melting it into ingots instead.
I’ve got two 32/20’s that I load for. A Smith M&P my grandfather bought about 100 years ago and a Ruger Buckeye convertible 😁
