Mainly on the topic of ground contamination.

I know to look for a building built after 1980 because of all the passed regulations such as asbestos contamination.

Oh an one more update the property is not on the Tennessee registry of contaminated properties.  

Depending upon the HVAC system in the house, it will also be contaminated and need to be replaced.Depending upon the vintage of the house, the tile on that basement floor (shown in one of the photos), should be tested for Asbestus.

I was going to raise it , but it is 6 inches from the driveway , it would either get hit or run over and crushed , It is the old style , a steel pipe with whats called a sanitary seal ( a big rubber plug in the 4 in steel with a compression fitting for the pipe no worries about contamination ) .

The EPA did say that any issues with the "spill" that happened on the property years earlier would be the responsibility of the new homeowner (me)- for the rest of time (to pay for cleanup costs) Like, if the neighbors found gasoline in their well, or if they started to work on the roads nearby and found gasoline contamination in the ground.

Wrong land, wrong system, encroaching and if the old system failed, am I contaminated!

Plus, I saved samples of all the contaminate flooring etc.

From what I understand, there is a cheap test you can do to determine if there is lead contamination or not.

using flooring nails and a power nailer which is the best way to go. so you don't beat the wood with dents from missed hammer blows.but if all you have is a hammer have at it but be careful.ok now for the staining.I recommend you get three cans of stain all of which should be close to your color of floor. going a little darker but not lighter. if you use three colors lighter by a shade if you use four colorscarefully use a darker shade against the nearest board of the old floor followed by your lightest shade followed by another darker shade followed by the middle shade. be sure to stay in the lines of the board and try not to go astray.actually using a rag turn it but dont worry too much about keeping your colors too separated the more contamination of stain from board to board the better it will give more illusion of uniformity in contrast this sounds contradictory to what I said about staying in the lines.