Paul's suggestion is correct, you should use an Op-Amp, though you can probably get away with just a single PNP transistor to do the job. Fuel gauges are something in between a current-meter and a Voltage meter when used in an analog system. The current should be low enough to not make sparks, but the voltage across the sender should be low enough for that same reason.
I did a project where i hooked the sender of my LPG tank to the Fuel-gauge on the dashboard, using an Op-Amp to invert the signal (the LPG sender was inverted) and correct the bias. The LPG tank was a 5v System so that had to be dealt with.
Totally. Your suggestion of Op-Amp type is also very functional (Though i believe that type is considered obsolete by some, but i don't see any reason to not finish all of them that were already produced if they suit the application. That goes for all obsolete parts in my opinion btw)