I agree with the if it's not broke don't fix it for the most part. If the car starts, and stays running, and is not blowing a lot of black or blue smoke out of the tail pipe then you should concentrate on other areas than rebuilding the engine.
I am working on this for my wife's 66. She uses it for a fair weather daily driver.
1) Tune-up: spark plugs, wires, cap, rotor, Pertronix (replaces points and condenser), gas filter, air filter, pcv valve, timing check, vacuum check, replace acelerator pump on carb if the car has not been recently re-built (this went on ours with no warning), check vacuum advance on distributor for proper operation (ours was rusted up on the inside and only cost $10 to replace). Also inspect any rubber hoses for dry rot (PCV hose, vacuum hoses, gas lines)
2) Check the alternator and voltage regulator. VR can be tested with an voltmeter. See if you are getting around 14.5 steady. New VR is about $10. Check coil. New coil is about $10. Can have coil and alternator checked at most parts stores.
3) Suspension: Check shocks for wear. Fairly easy to replace and don't cost much. Check tie rods and ball koints for excessive wear.
4) Brakes: If can't afford the disc brake upgrade at least ensure the drums, wheel cylinders, springs and shoes are good working order. Also, a dual MC is a must for safety. And bleed the entire system. And ensure the emergency parking brake is operable.
5) Cooling: Repalce the upper, lower, and bypass hoses and thermostat along with the coolant.
6) If automatic trans check the ATF, if it is varnished have a transfusion of the TC and trans.
7) Oil/filter change. Use a quart of the Marvel Mystery Oil in place of a quart of regular oil.
After this you should have a dependable daily driver, until something breaks.