You've chosen a good niche to collect, for certain - old enough to be rare, not so old as to be phenomenally rare or super expensive.
Those print-stamped decks were stamped as such to show that taxes didn't have to be paid - notice none of the ones with government stamps have a tax stamp stuck where the flap meets the box, as a seal. The government also had a tax-free stamp seal that was used for government-issue decks at that time - there's a good article on it in a back issue of Card Culture magazine.
Consider as well that some servicemen probably got decks sent to them in the mail by the folks back home. You can look at tracking down common, popular decks of the period that weren't necessarily government-issued, if you wanted to expand the collection scope a little.