Assuming that you want to tell the difference between the real SuperBee and a rebody or clone.

Look for the proper VIN rivets on the dash VIN, make sure it matches numbers with the fender build tag, the radiator support, and the trunk rail numbers. Check for filled trim holes on the fenders,doors, and quarter panels where the Coronet 440 and 500 had trim. Dash is rectangular speedo on the 440 and 500 and some R/Ts but has round Charger guages on SuperBee. NO chrome trim surrounding upper dash/radio/glovebox. 3speed wiper motor if the car has a twin scoop hood. Number of leaves in the rear springs.

Some or all of these could have been modified at some point in a car's life. If all have been modified then I would think the car is a rebody.

Take a person who knows what they are looking at before putting your money down.