Interesting developments there
alpapilot.
4. Stick an extension tank in the hold and run a B747-400 to Sao Paulo.
The two problems that I see with fitting an ER style tank in the forward hold of a non ER B744 are:-
1. The potable water tank is located in front of the CWT and thus would cause some difficulties wrt fitting the new tank and integrating it into the fuel system (on the ER's the water tank was moved to the bulk hold so that the AUX tank sits immediately forward of the CWT & "jet pumps" transfer the fuel (almost 10 tonnes) to the CWT at the appropriate time) and
2. the weight of the tank and fuel would seriously eat into the payload that a standard B744 could carry on long sectors. The ER's have a freighter wing and stronger landing gear which allows a 15 tonne increase in MTOW so that the extra fuel can be carried without adversely affecting the payload. The option to fit a second AUX tank to the ER's has not been bought by any airline as it would reduce the payload.
possibly even orders for the B747-800
Now that aircraft will be a great revenue generator.