I recently acquired several sealed decks of early to mid 1940's vintage playing cards, when I got them home I noticed an odor. I placed the decks in a ziplock bag for a few hours, I then opened the bag and gave a sniff. The odor was unmistakably that of cigarettes and pipe tobacco. I then decided to carefully open the decks and inspect the cards. I very cleanly cut the tax stamps an I found the outside cards on every pack to be yellowed, presumably from sitting in a smokers home for decades.
It may not be worth messing with, but does anyone know of a way to clean the yellow off of the cards that were on the ends of the stack of cards (against the inside cardboard package)? I'm not real worried because I did not spend much money on these, but the decks are in like new condition except for the yellow ace of spades and the yellowed back of one of the jokers.
I remember a sports card dealer use used to use lighter fluid to very carefully remove dirt and adhesive sticker stains from valuable baseball cards. The composition of the cards is a little bit different but the surface of the cards are similarly coated so you might find good results. I'd suggest practicing on a cheap deck of modern cards first, a deck you don't care about ruining, just to work on application technique and to test the impact of the cleaning fluid on the coating of the cards - use a coated, foreign-made deck or something US-made before 2009 that's of decent quality. (The reason for this is that in the US, manufacturers are now required by law to use more easily recycled materials when making cards, including coatings that aren't petroleum-based. USPC makes their new cards today with a starch-based coating.) Use a cotton swab and a very gentle stroking motion when applying, and in light quantities, then see how the results turn out.
There's a very good chance you won't be able to get out years of smoke stains, particularly tobacco smoke, but it's worth a shot. If that fails, you could just try replacing the stained cards - there's a decent market for old decks and for single cards as well.
You also have to consider there's a chance that despite the tobacco smoke odor that the yellowing might simply be a result of age. Yellowing from age, to my knowledge, isn't something you can reverse. I can understand the smell of the tobacco permeating the tuck box that the cards resided in, especially if the deck wasn't sealed with cellophane on the outside, but for it to get into the cards in the box means that the home they were in must have been a veritable proving ground for one of the major tobacco companies...unless it's simply natural aging that caused the yellowing.