The system is 40 years old, about double the average life span.
If you have the money, replacement will be a good idea, every aspect of that system is deep into its failure range, any money you spend on it will be a waste longer term.
The compressors and motors however are replaceable, $800 to $1,200 to replace the compressor, $400 to $500 to replace each of the two blower motors. A refrigerant leak repair and refrigerant recharge will cost you $400 to $500 as well if the new R-22a refrigerant is used not the now obsoleted and very costly R-22.
That is way too much money to spend on a 40 year old system in my view.
Let me know the region of the country you are in so that I can assess the load conditions, and size of your condo, and if you are on the top floor, or a floor somewhere in the middle of the building.
Tell me how your system is laid out, a few photo's taken at a distance of 10 or 20 feet will allow me to put it into perspective, I need pictures of the unit outside the house, and the unit inside the house.
Use the paper clip icon to attach the pictures.
We can go from there.