I have procured a small spot welder known as a “Dial a Weld.”  I believe it was used in the 1970s to weld the metal frames for braces.  It appears to be a fairly simple device that uses a rotary telephone dialer for consequent impulses from an electrical capacitor.

I have not been able to track down a user’s manual or find a user.  Any provided assistance would be welcomed.

@Mouse , the internet is a friend (photo provided below).