Of course hind sight is always 20/20, which bring me to the question: If you wanted a 2000 model, did it no occur to you to sell the 1987 and just buy a 2000 model? As all the other people have said moving the chassis number from one car to another, you have committed a crime. That is a crime in all countries of the world. Think about it: the chassis is different, the body is different so basically you have a totally different car with the chassis plate and papers from a totally different car. How can you justify that the car you have "created" has any DNA left over of the old car? So basically you are running a fake car on 1987 papers. I bet you thought you would never be stopped by the police and would get away with it. As @dani_kk and @chinyoti and others have said, There is no way out from this mess.
Despite what may happen, certainly the car is no longer re-sellable.