WATCH-CRAFT Mainspring 3871W for AS 1052 / 1054 including GP Shell - Alloy

WATCH-CRAFT Mainspring 3871W for A.S. 1052 & 1054 caliber movements and variants including the Girard Perrgaux "Shell" Pocket watch. (see images) plus perhaps similar ébauche watches, white alloy. The are from the C & E Marshall system. See image for precise characteristics. I specialize in hard to find watch parts so I usually have whatever you might need and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.