Identifying proper capacitor for HVAC
Buy a 50-3 dual capacitor. Titan part number TRCD503 is a good replacement. Just be sure to double check part numbers because manufactures offer both round and oval shapes. If it doesn't fit in that original mounting hole, you might need to buy a bracket for it and mount it yourself.

You can also leave the compressor capacitor in place and install a separate 3uF fan capacitor. It won't hurt the dual capacitor to have its fan terminal unused. Just be sure it's voltage rating is more than the line voltage so a 370 or greater volt rating is fine. Make sure the value is 3uF and the capacitor construction is of the film type.

My opinion: replace the compressor cap as well. Especially if the unit is 10+ years old.

If you add a separate capacitor, make a note on the units schematic for future reference with a service date.

By the way, that equipment grounding conductor (EGC) looks a little on the small side. Should be no smaller than 10 AWG for 30-60 amp circuits.