I had a 25 year hiatus from shooting, my IMR cans say Dupont and Bullseye says Herculese.
My I4198 had a brownish tint and acrid smell so I dumped it. The I4350 and I4064 seem OK. These are metal cans, not plastic.
Interesting, the 4198, Bullseye, and Unique old powders were less dense, meaning for a given setting on my powder measure they threw lighter charges than the new powders. Throwing 5.0gr of Bullseye on the old powder was 5.5gr of the new batch.
I had some T/C loads (357 Herrett) with old 4198 in them. On the range I got vertical stringing with them, like the velocities were erratic. Years ago I had them chronographed, they had a low SD and my best target was 1-1/4" at 100 yards. I pulled the bullets and dumped the powder and will reload them with fresh.