Maybe you can find someone traveling to the states & ask them to pick some up for you.
There are so many Brits visiting here, because of our weak dollar (which makes everything half price for you) that you must know someone who's coming. Or if not, come yourself!
From what I've heard, Brits come here for weekend excursions, with empty suitcases, and leave with them full of stuff they've bought. (Some things, they buy cheap here to take back home to sell for a profit - like designer handbags).
I guess it is a lot of trouble to go through (fly in, buy designer gear to scalp back home, to pay for your trip), just to get some outdated film. But I've heard of crazier excursions than that!