1969 L89 Chevelle convert

I'm trying to get an idea on the general concensus of the rough value of a 1969 L89 chevelle convertible. The car is local, very rough, but has a matching numbered drivetrain. It is a red, black top, and interior, 4spd car. It is pretty rough needing quarters and most other sheetmetal. As of yet there isn't any docs, but the carpet and tank are still in the car and haven't been removed yet to check for a buildsheet. There is a possibilty that the car might be for sale as well. Any help appreciated.