I recently purchased some carbon comps from Allied Electronics for those "special" sets where I'd like to retain the original look. Also, they were dirt cheap
Check out the bag they came in.
Along with the 1/2w 100K resistors inside was this humidity strip and some silica gel desiccant.
It seems to have helped. Every resistor is +/- 5% with a bunch being under 100K.
I spot checked a few from my non-environmentally sealed stash and all are high but still just within tolerance.
