Does your QLD license have the even dodgier renewal sticker on the back of it ?
Last time we were in the states (month or so ago) my wife and I were carded at a bar and all we had with us were our QLD licenses. The bartender took them both, looked at us and went to talk to his manager. Eventually got the drinks without a problem, but he did say the only reason they let it fly was because a) neither of us looks under 21 and b) despite both of them looking like, as you said, childish forgeries, two of them together lends a bit more authority to the situation.
The other thing I find that always gets the yanks is the order of month and day in the date. Especially since my birthday is the 13th.
I've rented cars in numerous countries throughout Europe and also in the US and never needed an international permit - even with my dodgy looking QLD license.