New voltage limiter questions - 67 Dart 270

I serviced over 300 instruments during a 8 yr. period. Then I retired.
Solder wont stick to nickel. The wire is welded to the studs. The wire/weld hardens.
Movement of the wire ( it moves as the bi-metal beam moves ) would cause it to break. This is why you'll find a ball of cement like epoxy material on top of the weld. This is/was to relocate the movement.