Like Davy mentioned, get a second openion and post a vid of your engine runing.
Taking into account that the car is over a quarter of a century old, a full tear down and re build may be needed to get rid of the knocks and was it you who mentionred of a smoking prob.?
As our car odo meters have been knownto run back every time they change owners,
your milage showing150k would have been passed decades ago.
TT
p.s, on a non related topic, check th operation of your cooliing fans.- common failiure in your model.