Marco Mainspring #263 for 0s Waltham Factory No. 2230 - Steel

Marco Mainspring #263 for 0s Waltham Model 1907, Factory No. 2230, steel, new in envelope. See image for further details. I likely have several of these so the one you get may differ slightly from the images. 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.