While you are initially looking for a container that would definitely be considered a large, you must find *and sign* the official log (which is inside the vault, in a micro). As with most gambling institutions, the odds favor the house, and only the determined will be granted entry into the bank for the stellar 'winner takes all' smile face.
You may get the log on your first draw, or it may take a few hits. Shiny coinage will hinder your odds, it may take some bouncy rubber balls to get to the end game, or you could find yourself rolling the dice. In typical fashion, the odds are even more stacked against you with some small random items for your frustration (or enjoyment 
). But when all is said and done, the house is beatable if you have the fortitude to keep at it, and not let typical frustration make you walk away leaving your valuables behind.
If you keep track of how many tries it takes (to put in your log), the house will know that you had the strength not to fold! 
**PLEASE PUT ALL OF THE PLAYING PIECES BACK IN THE CASINO AND SHUFFLE IT UP FOR THE NEXT UNSUSPECTING SOUL BEFORE RETURNING IT TO IT‘S HIDDEN STATE.**
*BRING YOUR OWN PEN!!* There are a couple inside, if you can find one of them. However, going to the Casino without a writing utensil would only end sadly if you had no way to sign the check (aka log) upon winning.
(Since this is meant to be a little bit of a challenge, please keep any trading even and do not wipe the house out. As more things are added by your fellow gamblers, the odds will increase in the house’s favor. (Naturally 
) Trackables are probably not a good idea, they could very likely get left behind in the house's vault.)
*~* Congratulations to KRUSEN4KACHE on his sweltering successful FTF casino trip! *~*