triple lightning zipper era?

[Keystonevintage]

Hello,
i have a b3 with as the title says a triple lightning bolt zipper, it definitely looks old. i dont have a photo to hand. any ideas would be appreciated

regards

 

[handymike]

Others know more than me, but I'd start here:
http://www.thefedoralounge.com/threads/dating-outerwear-by-zipper-design.73884/