I'm curious why is there a notch on the strike side main spring on a Gilbert Movement? Is there a real reason for it? Is it suppose to be there? If so where can you obtain it? Where can you find out the length of the needed spring for a Gilbert Movement? It was my first Antique Clock. A beautiful large Porcelain Gilbert case is in perfect condition. I would be more than greatful for any conversation or help with this matter. Hooked on Clocks ever since I got her.