Comsco Mainspring #1040 for Waltham 12s Colonial B 1924 Factory No. 2237 - Steel

Comsco Mainspring #1040 for Waltham 12s Colonial B 1924 Movements, Factory No. 2237, steel, new in envelope. Distributed by Burton M. Reid and Sons. See images for precise mainspring specifications and other 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.