Rhett,
Not sure we know an exact answer. The tin pictured on my website had a paper band on it that read something to the effect of "2 baseball picture cards placed at the bottom of this box."
While it can be said without question that the tins held the cards, it cannot be said with any degree of certainty that the soft packs held cards.
Here is the link to the tin:
http://baseballandtobacco.com/n403.htm
Note, I have also seen Yum Yum pails. Again, however, I have not seen any proof linking pails to the cards.
- Jon