Marco Mainspring #483 for Hamilton 6/0s Model 979 No. 2621 - Steel

Marco Mainspring No. 483 for Hamilton 6/0s Model 979 19j movements and likely others as well. Factory No. 2621, steel, new in frail envelope. See images for further details. I likely have several of these so the one you get may differ slightly from the images. I specialize is hard to find watch parts and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.