Since it's in the database, is there any documentation available for the car ? P-O-P, dealer invoice, title histories ? If not, depending on the state, the DOT might be able to give you paperwork on the car for a fee - I got full docs on two of mine verifying the Z options and all options ordered with the car, plus the MSO's from Chevrolet to the assigned dealers for a few bucks (lucky because both cars were sold new here in my state, the DOT photocopied and microfiched all of the paperwork). Worth a shot, although nowadays they will blackout the names of the prior owners due to the Federal Privacy Act, which would be no bad deal if you can document the rest of the car - that ends a lot of speculation about what the car started life as, then the only thing you have to worry with are restamped "original" drivetrain components.
All in all, a pretty car - a few details need correcting, but it looks like a very good and nearly finished Z. I wouldn't kick it out of the garage for leaking fluids. Good luck on your deal.
Just my opinion -