I think you've already dealt with most of the common ones. IIRC, you've replaced the radiator and heater hoses, (bypass hose as well?), plugs, points, condenser, cap & coil. A spare ballast resistor in the glove box is/should be standard equipment on these cars. Master cylinder and wheel cylinders? Flex hoses? Do you regularly use the parking brake to keep it exercised? You do engine oil & filter changes regularly? And a shot of grease into all of the front end components every oil change doesn't hurt either. Speaking of grease have you disassembled and greased the u-joints on the drive shaft? 48 year old grease just doesn't work like new grease does.
There's a maintenance schedule somewhere in the owner's manual for your car. It will outline "Normal" service and "Heavy Duty" service. I always recommend to people that they follow the "Heavy Duty" maintenance schedule. If you were driving the wheels off the car, following the HD schedule would make a difference in your wallet, but using the car as a pleasure only, occasional use vehicle, it shouldn't.
Replacing vacuum hoses (brake booster, PCV valve, vacuum advance) every time one of your kids graduates from one school to the next is sufficient.
Replacing the rubber hoses on the gas lines with ETHANOL RESISTANT hose is a must if you haven't already. Ethanol does just NASTY things to the steel gas tank, steel fuel lines and the rubber hoses. It also means you'll need to rebuilt the carb every few years to clean out the silt that will accumulate. No fuel filter available can catch that silt.
Or long story short, concentrate on the things you haven't worked on yet. They're getting ready to conspire to get you unless you get them first!