If you & your dad are comfortable with the car, it is
advisable if you keep it. For such old models, spare parts &
even reconditioned engine blocks & gearboxes are easily
available & it is not as expensive as the newer models.
Those parts for old models are meant to be exported to 3rd world
countries & they are sold at a 3rd world country price. Before
you get robert by the workshops, you can take your user manual
& shop around at Jalan Besar or Serangoon area, where such
spare parts are available.