1986 Ford Escort 2-Door 2.0L Diesel

1986 Ford Escort diesel. body clean no rust some small scratches one or two small dents. interior pretty good for its age but a sun damaged dash. Starts hard. might just be weak battery but once running runs ok. Needs heater core replaced I have a brand new one just never installed it so can't drive the car very far before it starts steaming up the windshield. I have a extra motor to go along with it I believe it has a leaky head gasket not sure though. The motors are Mazda RF 4 cylinder diesels. known for getting great mileage the guy I got the car from said it got 42 mpg I didn't drive it enough to find out. I bought the car and the coolant leaked out the heater core and blew the head gasket the first day I bought it. I bought a used engine and installed it and bought the heater core never installed just lost interest in the car. The mileage on the odometer says 26048 I don't know if it has rolled over. Also I'm not sure how many miles are on the motor in the car.