Fuel Pump access

This is in reference to the fuel tank leak problem that I have had since the past six months:
I have removed the bottom back seat to expose the sending unit underneath the 3P connector. From here, the sending unit looks pretty dry (no sign of fuel smell of leak). Am now trying to similarly locate the fuel pump without going underneath the car - Is this possible??? I believe the fuel pump is towards the back of the car, in reference to the sending unit.
I went underneath the car and saw the fuel leaking towards the rear right end (as you face the trunk) of the tank (towards the back of the car, rather than where the sending unit is), but it is coming from somewhere up where the fuel pump might be - so suspect the leak might be a crack, hole, or at the junction where the fuel pump connects to the tank.

you have to drop the tank to gain access to the fuel pump. is your car rusty at all? thats the only pain about dropping tanks here in ny

Underneath it is not rust other than a spot here and there. It has been nicely coated with the black tar undercoating, by the previous owner. The thing that is rust is the two bolts that hold the brackets holding the tank, and there is some rust near the half partition of the tank, just where the tank vanishes into the upper mold of the car.
I have the biggest worries:
(1) Once I dismantle the hose covering and the brackets to loosen the tank to drop down, because there may be rust in the upper part of the tank, it may not fall down freely - If this is the case, I am afraid that if I try to pry it down, it might give way and destry my chances of repairing the tank, or replacing the tank.
(2) This is more a question - If the car has no problem other than the tank leaking fuel if fillup is 3/4 of tank or more (It never leaks when I fillup to about 60% of the tank), will I be able to use the same sending unit and fuel pump when I replace the fuel tank, or do I have to buy sending and pump?