Marco Mainspring #860P for South Bend 0s Mainspring for 1st Model No. 12528 - Alloy

Marco Mainspring #860P for South Bend 0s movements, Factory No. 12528, alloy, new in envelope. First time I can recall having these in alloy so grab them while you can. I specialize in hard to find watch parts and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.