brand new gas tank

I took everybody's advise and bought a new tank. After looking at the old one, I'm sure that this is the way to go! I did the test fit, and it's ready to go!

I have a few questions for those of you who have traveled this road before......

My new tank was sprayed with some type of preserving oil prior to shipping. I noticed that the inside of the tank also is covered with this oil. Should I wash the tank with soap and water, then rinse with cheap isopropol alcohol, or ignore the light oily film? Other than paint, is there any prep work that I should do?

As always thanx in advance for your advice!