Welcome.
Try contacting a repair company such as Syntaur if you are in the USA or similar in your own country.
The socket looks like the S-Video ones I used many years ago so at worst you could make up an adaptor and connect up a generic three pedal unit after verifying its compatability.
First I would check the internal conditions of the units you have.
Not sure what you have included the lower image for, there seems to be a broken component of some sort.