Found two hand crank pumps that looked interesting.
First looks better quality than second. But remember, these would be for getting access to gas in a place like a gas station. Even when the pumps cant get any more, there is still plenty in the very bottom of the tanks. And every gas station has pretty easy access to the tanks, just lift the lid in the ground. To attach rubber hose to these you will have to use a tightening band of some type - plenty at Home Depots and such.
If you need to get gas from abandoned or 'found' cars, just use length of rubber hose and good ol suction. Maybe buy a box of Tic Tacs with the hose.