I own a 87 300SDL. The transmission is slipping. I have tried adjusting that T handled thing and changed the fluid but the tranny is going.

I need to get rid of the car and I don't know what my best option is. I will describe the condition of the car if you could let me know what its worth or what to do with it I would appreciate it. I replaced it with a 2003 Acura CL type-s 6spd. Very happy.

Anthracite grey. Paint is missing from hood, roof, and a little on trunk. Body is straight and clean. All lights work. Interior is in good Shape. All black. Dash has two small cracks in it by speakers otherwise its perfect. Wheels were repainted but are peeling. Tires are good. Brakes are good. Suspension is good, shocks were all replaced less than 3 years ago. Parking brake was disconnected by previous owner, parts are in trunk. No radio it was stolen. Windshield is about 6months old. Seal was replaced also. At least two glow plugs are out. Battery is less than a year old. All windows work. Air conditioner is broken. Climate Control works.
A friend of mine has an identical car and is much more experienced with mercedes diesels than I am. He thinks the engine is in great shape and it has little to no blow by. Odometer stopped at 299K. There is less than 312K on the car. Sunroof seal needs to be replaced. I own one and the sunroof opens and closes. Full size chrome spare. This car has a number 14 head. I believe it is cracked also. The car starts runs and drives fine. I don't know if the head is cracked but the coolant system stays pressurized much longer than it should.

Your comments on my car's value and whether to sell or scrap is much appreciated. THANK YOU.