The opening in the plastic socket is smaller than the ball stud on the linkage , I'm not sure how you could insert the ball into the socket even if you had one . I would assume the ball and socket are manufactured as a unit with heat providing the plastic at the collar of the socket to soften then the ball inserted then the heat softened collar of the socket would need to be closed slightly around the ball to ensure it doesn't pop out. If you remember the site where a socket can be found ,let us know as these sockets must be inexpensive and I would buy a few and try to install it properly as I have a spare wiper transmission that has also failed.

Ben