clearing gas tank, sitting 5 years

I am preparing to bring home a project car my father left to me. it's a 63.5 galaxie Z code with a 427 + 5 speed.

the car last ran 6-7 years ago and I'm sure has less than half full gas tank.

the car needs a few engine parts and some assembly but it's about 80% complete.

anyway, i need some advice on what to do with the gastank?

can i use the fuel pump to drain it?

how do i check it for rust / contaminate?
is cleaning it with vinegar good for everything, or just rust?
opinion, would you hassle with this, or replace it for $420?

input is much apprec

I would take it out remove the pick up and look inside to decide what to do. BTW if original it had a 4sp.

I have sealed several fuel tanks with RedKote. Its easy to prep. Put a chain in the tank after removing the sending unit and put in a degreaser and warm water. Tumbling the tank with the chain loosens the rust. Then wash the tank out again with water. You can use Acetone to remove he remaining water. When the tank is ready, put a quart, preferably two, of RedKote in the tank, seal all the openings and slowly tumble the tank. Then drain out the excess Redkote and let the tank set at least 48 hours. Follow the directions and you shouldn't have any problems.