Aside from the $1k difference, I like the "passive" solution of dirt and vapor barrier but I want to make sure it will work.If I'm really lucky, maybe somebody in the Tulsa area could suggest a contractor to do this for me?  

The solution will lie with the city/county planning and zoning dept. who should be able to tell you the required process to get this resolved.  

Ask questions and you'll receive different perspectives, opinions and solutions.

And if you get that far, and the appraisal does not come out, then walk away.The easier solution is to just find another turnkey with better deals.  

By asking better questions, and being interested in the answers, you can discover what the Seller’s problems and issues are and then offer a solution.

This contractor is creative, underbid the job yet still honored their estimate, and came up with solutions I wouldn't have.

Noticed your post and wanted to extend a product idea that our firm has that could be of assistance to your situation, if you haven't found a solution already. 

Repaint exteriorShould do's Complete rewire from 100 amp service with tube main breakers to modern 200 amp service.Replace old 1950's windows that are cheap aluminum balanced or wood channels that have been pained shut, but at the front of the lot near the road in the front corner of the property.

We technically couldn't do a thing about it but this tenant wanted her out after a few days but didn't want to be a bad guy about it.Our solution was to pay the downstairs tenant $250.00 to move out within 5 days and this forced the nightmare tenant off our property.

Keep learning and growing your niche in real estate and refer to BP as a solution to any answer you encounter.