I would pull the hitchead pin and clean it and grease it , inspect all the springs, and spray em with some good corrosion preventative spray like CRC or
poke here
on all sliding parts and inspect all teh bolts for pitting corrosion and the bolts at the frame as well for tightness and condition
anything that looks worn out.... replace it. locking jaws for smooth operation and grease their guide pins, might need new C clip s if you pull teh pins.