My A/C is to old and they don't make replacement capacitors?

What is the brand of the units?
Our front heat pump is only 13,500 and both are Coleman.
No problems now but did have to replace a capacitor, and sued a higher rated cap.
And recently fan slid down shaft of the rear 15,000 unit and ground itself into base plate. Coleman repaired it.
Front unit quiet but the rear is like a Chinnook engine spooling up but boy does it through out cold air.