The plot thickens… Wow… So after all of this, you're saying this could actually be a legitimate deck??? I don't know how I feel about this… Perhaps consulting a few more veteran collectors… I don't see why they'd ever print such a deck without the Bicycle Joker or Ace of Spades, when this is indeed a "Bicycle" deck… Not buying it… I think the checks and balances system, albeit now more advanced, wouldn't have allowed this…
It's not as far-fetched as it may sound.
I'm sure you recall when USPC moved from Cincinnati to the suburb of Erlanger. At the time, USPC still had a lot of left-over, printed-but-unused deck boxes for their major brands that were labeled with the Cincinnati address on the side. Rather than recycle them, they opted to use them and switched the deck seal from blue or red to black.
Flash back to circa 1950 (and bear in mind this is another of my famous educated guesses). The Uncle Sam deck is being phased out, but they still have plenty of uncut sheets printed, or perhaps some hundreds or thousands of assembled decks - cards were mighty popular in the population in general and among the military in particular, so it stands to reason they might end up in such a situation when the brand was no longer being ordered by the government for their troops. Back then, they didn't even recycle - they would have ended up in a trash bin or a furnace. They probably couldn't sell them in the Uncle Sam boxes - they're marked as tax-free and for government use, and maybe something in their contract prohibited civilian sales under the Uncle Sam brand name. Rather than waste them, they print up Bicycle boxes with the same back, stuff them with Uncle Sams and sell them until they're gone.
It's entirely possible that they would have continued using the back under the Bicycle brand name with actual Bicycle playing cards since that design was so familiar to the WW2 vets who used them in wartime under the Uncle Sam name. It would be similar to the reason why Irish whisky got displaced by Scotch whiskey as the most popular spirits among most American men at about the same time - before the war, Scotch distillers didn't muscle their way into the American market going up against Irish whisky, choosing to focus on Europe. American soldiers stationed there acquired a taste for the drink and started buying it in large numbers when they went back home.
Again, it's educated guesswork - except for the part about the whiskeys, which I learned on the History Channel. And of course, the part about Erlanger, which is common knowledge around here.